EIGHTH GRADE: Stars Elsie Fisher and Josh Hamilton; written and directed by Bo Burnham; 93 minutes; R. Critic’s rating: A-.

As singer Edie Brickell once asked, not terribly long ago, “What I am is what I am. Are you what you are or what?” Silly wordplay in a too-catchy pop tune, maybe. But certainly the type of question that a young teen, experiencing what once was called an identity crisis, might ask her reflection when looking into the mirror, obsessing over perceived imperfections and social-media traumas: “What you see is what you get. But who am I, really?”

Personal identity, as might be recalled about those days of acne wars, puppy love, and self confidence that waxed and waned with the bell schedule, could be entirely wrapped up in what others saw in you. Or what you imagined they saw in you.

So for the sake of emotional self-defense, you locked yourself into your bedroom and used a journal – paper? on a laptop? on an audio device? — to create the façade of a more confident you. And it all vanished, of course, the moment you walked into the birthday party of the nominally best looking and most popular kid in school.

So it goes in “Eighth Grade” with Kayla, the middle-schooler brought to life via Elsie Fisher‘s remarkably lived-in performance. All imperfect skin, blue fingernail polish, introversion, moods that are sometimes silly and sometimes pouty, and unpolished social skills, she’s forever wrapped in a digital cocoon. Her earbuds are plugged into an iPhone blaring teenypop, and she’s forever scrolling through Instagram and firing up snapchat.

Kayla’s always making YouTube-bound videos of confessional-style inspirational talks, spiked with plenty of “likes” and shot in not always flattering close-ups, that belie her own insecurities. “The topic of today’s video is being yourself,” she says during the movie’s opening sequence, staring straight into the lens as the camera gradually pulls back to reveal her butterfly-decorated shirt, dark sweater, and makeshift bedroom TV studio. Later, she titles another clip “How To Be Confident.”

At home, Kayla suffers through life with loving single dad Mark (Josh Hamilton) who, you know, just doesn’t understand, asks too many annoying questions, and further bugs his daughter by encouraging her to “put yourself out there.” It’s a message that she later co-opts for one of her video chats.

In one of the film’s most affecting sequences, set in the backyard of the family’s modest home, Mark quietly offers his own glowing assessment of Kayla’s personality and talents. It’s just the right antidote, at the right time, to her frequently misguided if overwhelming feelings of worthlessness. And, as directed and written by remarkably assured 27-year-old filmmaker Bo Burnham, these scenes are not overly saccharine or drenched in sentimentality.

At school, Kayla suffers the indignities of sitting through a your-body-is-changing video featuring an instructor who says things like “it’s gonna be lit.” She’s also stuck taking on cymbal-crashing duties in the meagerly talented school band, navigating mean girls in the hallways, and melting in the presence of Aiden (Luke Prael), a handsome, trim boy with smoky eyes and, as it turns out, a dullard’s personality.

Outside of school, there are bright spots, including the attentions of a nerdy but attentive nice kid (Jake Ryan) and a friendly high-school girl (Emily Robinson). And, in a harrowing if sensitively shot sequence, there’s an older guy who attempts to take advantage of Kayla, and, when rejected, tacks on some gaslighting for extra measure.

Burnham, who sparked his own career as an actor and filmmaker via a series of comic YouTube videos, takes an approach to his young characters that’s neither dumbed down nor overhyped. It’s a bit reminiscent of the young heroines of last year’s “Lady Bird” or 1995’s “Welcome to the Dollhouse.”

Unlike the blemish-free kids in Nickelodeon and Disney fare, and most network sitcoms and family dramas, these teens come with imperfections and believable challenges, and conflicts that are never resolved. That  authentic vibe is heightened by an indie production style that’s clean, direct and unshowy, and the antithesis of high-gloss Hollywood.

No, “Eighth Grade” is not remotely a documentary. But Burnham’s coming-of-age comic drama sometimes points in that direction, particularly via the videos within the movie — scout around, and you’ll see some that look and feel exactly like those in “Eighth Grade.”

It all strikes closer to middle school reality, or ordinary, middle-class, middle-America anything, than practically any other recent film or TV production. It’s a fresh and funny surprise gift, driven by Fisher’s revelatory performance. We won’t soon forget Kayla, her typical teen trials and tribulations, her evolving sense of self, or her supportive dad.

Opens Friday, Aug. 3 at Tampa Theatre, Cobb Grove 16 & Cinebistro Wesley Chapel, Goodrich Riverview 14 GDX Gibsonton, and GTC Beacon Theatres 12 Brooksville.