Elsie Fisher stars as Kayla in Bo Bunham's "Eighth Grade."
CNN  — 

There’s a scene in Bo Burnham’s “Eighth Grade” where the main character, Kayla, scores an invite to a pool party thrown by a popular peer and attended by everyone the shy girl wishes she could emulate.

The brilliance of this standard teen movie moment, however, is that by this point in the film, you’re so immersed in the awkwardness of Kayla’s life, that her long, timid walk from the guest bathroom in her lime green one-piece to the pool almost makes you sweat with anxiety.

Sure, they’re just teens, not velociraptors. But watching the middle schooler bashfully take her place in a small corner of the otherwise active social scene, you wonder if Kayla would almost prefer being dinosaur lunch to the silent judging she perceives being directed her way.

“[The movie] shows just how big such small things can feel – like walking down from the house to the pool,” says Elsie Fisher, the 15-year-old actress who plays Kayla. “And the scene just portrays kids in the [way] they’re viewed by other kids, which is the scariest goddamn things alive.”

In real life, Fisher is the furthest thing from scary. In fact, she talks to people with an unapologetic enthusiasm that most reserve for best friends they haven’t seen in a long time.

Kayla shares this energetic method of communication with her portrayer but rather than coming from a place of friendliness, it’s rooted in frantic discomfort, particularly when engaging in conversations with kids her own age, who are a little too consumed with their own ambivalence to notice Kayla trying very hard to make and have friends.

Much of her dialogue in the film is delivered directly to camera as Kayla films first-person, self-help style YouTube videos meant for other kids her age. Little watched, the videos end up being a chronicle of a teen giving to others the advice she wished she knew how to put into action.

Fisher was one of the first people Burnham saw audition to play Kayla and says her connection to the material was instant.

Elsie Fisher stars in "Eighth Grade" from director Bo Burnham.

“Every other kid that came in to audition felt like they were a cool, confident kid pretending to be shy, and she felt like a shy kid pretending to be confident,” he says. “Elsie really understood the layers of the performance, and that’s an exceptional thing to be able to do when you’re an actor at any age.”

“Eighth Grade” is Fisher’s meatiest on-screen role so far of her career, but not her first major part. Fisher was the voice of Agnes in the first two installments of the “Despicable Me” franchise and has a long list of acting credits.

Despite her resumé, she admits getting work has been tougher “because I think roles for teens, and especially roles for teens with acne, are not plentiful.”

Luckily, authenticity was Burnham’s goal and, it turned out, key to “Eighth Grade’s” magic.

He wanted kids who were in the eighth grade to be playing eighth graders – simple in concept but far from the Hollywood standard, where older actors are often cast in roles meant for kids several years their junior. That method, says Burnham, is reflected on screen.

“You can see that they’re older kids pretending to be young…and the way you remember being that age is different than the way you were at that age,” he says. “We wanted it to feel like kids living their experience and looking out from within their experience.”

Beyond casting, Burnham had the challenge of writing, as he says, dialogue for “kids that can’t speak,” decorating bedroom sets for emerging adults who might not yet have a distinct style, and in as many ways as possible, embracing the messiness of not yet knowing one’s self.

“You’re growing into all those things,” he says. “So we wanted to show the work and the show the failure because that’s the beauty of it.”

Actor Elsie Fisher and director Bo Burnham of 'Eighth Grade' attend The IMDb Studio and The IMDb Show on Location at The Sundance Film Festival on January 20, 2018 in Park City, Utah.

Thanks to YouTube, finding the voice of Kayla was easier than expected for Burnham, who got his own start as a comedic performer on the video platform. While watching hours of videos, he said he found that “boys talked about Minecraft and the girls talked about their souls.” That inspired him to tell a story from the perspective of a girl in her early teens.

“I was very sensitive to the fact that I was a man in charge of this story, but I also had to trust the fact that it seemed to be working,” he said.

He got it very right, according to Fisher – except for one thing. In the original script, the teens’ social media of choice was Facebook, which caused Fisher to joke, “Nobody uses Facebook anymore. What is this about? My aunt?”

It was changed to Instagram and Snapchat.

Burnham says his overall aim was to use a middle school student to tell a story rooted in the same pathos that drives any good movie about a person’s deepest battles.

“What if you made a movie about an eighth grader that took her experience as seriously as, you know, ‘The Wrestler’ did?” Burnham says. “I hope it’s really about being alive right now. The human condition is often only for cowboys and male poets in movies, but why can’t a 13-year-old girl be a conduit for the current experience?”

Fisher puts it even simpler: “I just want people to relate to Kayla and feel less alone in their weird experiences.”

“Eighth Grade” will debut in theaters on Friday.