“Smiley Face,” about a pot-addled would-be actress stumbling through a long, weird day in Los Angeles, is a contradiction in terms: a “stoner” comedy with a purpose.

Directed by Gregg Araki from a screenplay by Dylan Haggerty, the movie at first seems a psychedelic lark, in the spirit of “The Big Lebowski,” “Harold and Kumar Go to White Castle” and other works distinguished by picaresque narratives and cumulus clouds of marijuana smoke.

Mr. Araki, a trailblazer of early ’90s queer cinema, can stage a non sequitur with the best of them. He gets plenty of opportunities thanks to his lead actress, the “Scary Movie” star Anna Faris, whose freakishly committed performance as Jane F. suggests Amy Adams’s princess from “Enchanted” dropped into a Cheech and Chong movie.

Jane is a giggly, flirty goofball whose perpetual buzz is cranked up several notches when she scarfs a plateful of cannabis-spiked muffins baked by her roommate. Intending to bake a replacement batch, she orders a large amount of product from a dealer (a dreadlocked, droll Adam Brody) whom she can’t afford to pay; accidentally destroys her cellphone while cooking the muffins; then arrives late to an audition for a strait-laced casting agent who reports her drug use to the police; and so on.

Despite its laid-back script, “Smiley Face” is as prankishly political as Mr. Araki’s “Doom Generation,” evincing a deep unease with the media-saturated capitalist nation that Jane crawls inside her bong to escape.

The film depicts Jane’s habit as pathetic even as it plays for laughs. At the same time, though “Smiley Face” suggests that the “straight” characters Jane encounters — the casting director (Jane Lynch); a bullying beat cop (Michael Shamus Wiles); a college professor’s wife (Marion Ross) from whom Jane steals an original copy of Marx and Engels’s “Communist Manifesto”; a couple of amiably clueless meat delivery men (Danny Trejo and John Cho); the humorless Brevin (John Krasinski of NBC’s “Office”), who likes getting his teeth cleaned because it makes him feel “prosperous” — are in thrall to an even more powerful drug: the myth of the American dream.

At one point Jane, who has somehow ended up at the meat-packing plant that employs the delivery men, deflects a supervisor’s ire by claiming to be a union organizer, then fantasizes launching into a Marxist soliloquy about industrial oppression of labor. Mr. Araki intercuts Jane’s rant with unsettling close-ups of meat being sliced, ground and liquefied.

The film’s title is drawn from a scene in which Jane envisions the sun as a smiley face. The implication is subtle but clear: Americans fancy themselves free-willed strivers who live in the best of all possible worlds, but they’re really sentient vegetables, rooted in comfort and nourished by manufactured images of bliss. Jane’s apathy-as-rebellion recalls a quotation from Stella Adler: “A junkie is someone who uses their body to tell society that something is wrong.”

“Smiley Face” is rated R (Under 17 requires an accompanying parent or adult guardian). It includes sexual situations, profanity and nonstop drug references.

SMILEY FACE

Opens in Manhattan on Wednesday.

Directed and edited by Gregg Araki; written by Dylan Haggerty; director of photography, Shawn Kim; music by David Kitay; production designer, John Larena; produced by Steve Golin, Alix Madigan-Yorkin, Mr. Araki, Kevin Turen and Henry Winterstern; released by First Look Studios. At the IFC Center, 323 Avenue of the Americas, at Third Street, Greenwich Village. Running time: 1 hour 25 minutes.

WITH: Anna Faris (Jane F.), John Krasinski (Brevin), Adam Brody (Steve the Dealer), Marion Ross (Shirley), Jane Lynch (Casting Director), John Cho (Mikey), Danny Trejo (Albert) and Michael Shamus Wiles (Officer Jones).