She’s not a part of the cast, but Mary Ellen Matthews has been a key piece of “Saturday Night Live” for the past 23 years.

Since 1999, Matthews has been the show’s official photographer, shooting the photos that you see every time the show comes back from a commercial break. These celebrity portraits highlight each week’s host and musical guest, and they’ve become as much a part of “SNL” as the opening monologue or “Weekend Update.”

“I always try to bring the joy,” Matthews said. “That’s my sort of maxim of how I operate: to bring the sense of playfulness, to keep it light. It’s also nice to have these quiet moments that are a little more introspective once in a while. I think it’s a good balance in the show.”

These portraits have been a part of the sketch comedy show since 1975, the year the show premiered. Edie Baskin was the photographer then, and Matthews picked up where she left off.

Every Thursday before a show, Matthews is able to meet with each host and musical guest to collaborate on a variety of looks or concepts. She comes in with ideas that might play off each subject’s personality or public persona. Or maybe it’s re-creating a famous piece of art. Sometimes it’s just as simple as putting Charles Barkley’s bald head in a sea of basketballs.

“And there’s always something organic that happens, so you kind of have to leave room for that,” Matthews said.

After each shoot, a little bit of post-production is needed to make sure the photos have the graphical treatment and colors they need to “pop” for the live broadcast. In recent years, Matthews has also dabbled with animated stills.

Because of the hectic nature of “SNL” production week, Matthews only gets about 90 minutes with each host and 20 minutes with each musical guest. But it’s thrilling, and she loves it.

“Each week is like the first week all over again,” she said. “You always want to do better than the last week, and you always want to provide the same fantastic, creative service to each host and musical guest and make it as fun for them and (make) their dream come true.”

And make no mistake: Even for some of the biggest celebrities, hosting “SNL” is a dream, Matthews said, and they usually come to the shoots eager to take part in the tradition.

“I feel the excitement,” she said. “I feel (them) thinking like, ‘What are we going to do?’ There are a lot of zany ideas. There have been a lot of funny concepts. I think it’s a time for them to let loose a little bit and just do this sort of trust fall.”

Adam Driver

Air date: January 25, 2020

There were no special camera tricks used for this image of Driver, who was hosting the show for the third time in 2020. Just carefully placed mirrors and a bit of patience.

“He’s someone who gets what we’re trying to do,” Matthews said. “Very collaborative of getting the right position and the right positioning of him within the mirrors and the right position of his hands. It’s really nice to get these kinds of images in the camera.”

Oscar Isaac

Air date: March 5, 2022

Matthews often references famous art in her shoots. This one is a nod to the René Magritte painting “La Clairvoyance.”

In Magritte’s painting, it’s a self-portrait of him painting a bird while he looks at an egg.

“I kind of was just like, flip it,” said Matthews, who brought in a prop chicken for the shoot with Isaac. “And now it’s a fried egg, and the chicken is not liking that very much.”

Claire Foy

Air date: December 1, 2018

Foy, one of the stars of the show “The Crown,” is perched on a swing while drinking from a teacup.

“We’re kind of leaning into her Britishness,” Matthews said.

The studio crew hooked up the swing for the shoot at NBC Studios. “That’s real,” Matthews said. “She’s actually hanging from a swing in the rafters in Studio 8H.”

Chance the Rapper

Air date: October 26, 2019

Chance plays an entire gospel choir by himself. It was fitting because in this episode, he was both the host and the musical guest.

“We did him in all these poses and put it together,” Matthews said.

Chance has also labeled himself a Christian rapper, and he references his faith in his music.

“This spoke to him,” Matthews said.

Kim Kardashian

Air date: October 9, 2021

“I was doing colored gels last year, and it’s a bit of like a long-exposure (photograph) and it plays with the accents on her dress there,” Matthews said. “I just think this is beautiful for her. A little bit more of her just feeling the moment. …

“She’s understanding what we’re doing with the light and the long exposure, so she’s aware of the process, and our collaboration came out beautifully there.”

Paul Rudd

Air date: May 18, 2019

“We found the couch and then Tom Broecker, our incredible costume designer, had this suit made,” Matthews said.

She said she couldn’t recall for sure whether the couch came like this or whether it was upholstered to match Rudd’s outfit. But it was all perfect for the playful Rudd.

“He is so expressive,” Matthews said. “He’s just the best, right? We all love him.”

Larry David

Air date: November 4, 2017

This was another example of how some of the best portraits aren’t planned.

“We just started playing, and, you know, a character evolves when you hand someone a pipe sometimes,” Matthews said.

She said this was David’s favorite from their shoot.

“I think he’s asked to use as a headshot or something. He loves this, too,” she said.

Jason Momoa

Air date: December 8, 2018

Matthews often tries to formulate ideas based on each subject’s public persona. But it’s also fun to go in the opposite direction — like putting Momoa, who often plays tough guys, in a goofy suit.

“There’s another shot from the same shoot where I had him in pigtails, and (his expression) is like ‘thanks a lot,’ that kind of thing — which is exactly playing against type,” Matthews said.

She initially wanted to make this photo an animation, but she spread it out as a still image.

“We talked about it, and he kind of gave me a couple moves at the end. And the suit just worked perfectly in a graphic sense.”

Regé-Jean Page

Air date: February 20, 2021

Matthews remembers the breakout “Bridgerton” star being “so beloved” during his week. “He just was such a wonderful, wonderful person to work with,” she said.

Like the Foy shot above, this plays into his British background.

“Maybe I’m overdoing the teacup,” she said with a laugh. “But we were doing something and we both just decided, why don’t you just bust through the other side of this? It was at the very end of the shoot. Just be playful and wreck the set. Why not?”

Daniel Craig

Air date: March 7, 2020

“He is definitely one of my favorites to photograph because, you know, he’s Bond,” Matthews said. “And for him to be standing as a subject is quite a thing, I must say.

“I’m a huge fan, and I just thought him giving these sort of glances and putting them together, it took the spy and gave it a little something comedic there.”

Donald Glover

Air date: May 5, 2018

This mirror wasn’t planned to be a part of Glover’s shoot.

“We were just using it to check looks and stuff, and it just became this reflective, amazing moment,” Matthews recalled. “Not usual for these kind of fun bumpers. But I think it’s really powerful.”

Will Ferrell

Air date: November 23, 2019

Every year, it’s tradition for Matthews to incorporate this same turkey prop into the Thanksgiving show.

“We have whoever is hosting the Thanksgiving show do something else with the turkey,” she said. “I think Matthew McConaughey was in the steam room and they both had little towels on.

“But with Will, I just thought of walking his turkeys there on Fifth Avenue. I just made it up, I don’t know. Like I wasn’t quite sure where we were going with this. Instead of walking your dogs, you’re walking your turkeys, and it became sort of this ’70s version somehow along the line.”

Dan Levy

Air date: February 6, 2021

“He’s such a vibrant person,” Matthews said of “Schitt’s Creek” star Daniel Levy. “So adding that vibrant color to that candid moment, it just seemed very him. There was nothing forced there. It’s effortless Dan Levy right there.”

Matt Damon

Air date: December 15, 2018

“The Christmas shows are always fun to do, and for this one I found a reference to the Beach Boys’ Christmas album where they’re decorating a Christmas tree,” Matthews said.

Like with other holiday shows, Matthews will start thinking ahead of time about ideas that can make each year feel different. She thought this one was a great match for Damon and his clean-cut image.

“Matt nailed it perfectly with this sort of pasted-on smile, ‘everything’s OK in the world.’ … I wanted each shot of him here to kind of be the same, and he rose to the occasion.”

Halsey

Air date: February 9, 2019

This photo of Halsey is another nod to an album cover: “Goats Head Soup” by The Rolling Stones.

“Mick Jagger is kind of covered in a silk the same way,” Matthews said. “We were playing Rolling Stones, and I was talking about the Stones, and I suggested that and she loved it. … And she is so present. She is such a collaborator. I adore her, her artistry. She’s a painter. There’s so much to her.”

Daphne

Air date: April 25, 2020

During the height of the Covid-19 pandemic, “SNL” aired some special “At Home” episodes where cast members would film segments at home while they practiced social distancing.

Matthews didn’t have her normal hosts or musical guests to take photos of, so she had to improvise, too.

Enter her dog, Daphne.

“We all had to just make do with what we had at home, and she became my subject,” Matthews said. “So I put her in a bubble bath with a shower cap and a rubber ducky. … It was not easy. It wasn’t actually that much water. It was more bubble bath. But she definitely looks like: ‘Please stop. Get me out of here.’

“I’m not sure how much she’s enjoying it there. But she was very patient, and I owe her a big biscuit for that one.”

The new season of “SNL” premieres Saturday at 11:30 p.m. ET/8:30 p.m. PT on NBC and Peacock. This weekend’s host is actor Miles Teller, and the musical guest is Kendrick Lamar.