Mistress America is Noah Baumbach’s second feature for 2015, and by far the strongest. His first effort, While We’re Young, parlayed an unconvincing generational-gap comedy into a weirdly-shoehorned meditation on authenticity in documentaries; Mistress America, thankfully, proves to be both a funnier comedy and a more insightful analysis of the blurred line between artificiality and authenticity.

As in the celebrated (and somewhat overrated) Frances Ha, Greta Gerwig pairs up with Baumbach as co-writer and star, playing Brooke: an energetic thirty year-old living life to the full and so forth in New York City. Though this time the real protagonist of the piece is Tracy (Lola Kirke), Brooke’s sister … sort of. Maybe relatability is overrated, but I really appreciated how well I could relate to Tracy’s college experience. Rather than finding tertiary education the enclave of intellectualism or hothouse of hedonism that fiction would have you believe, Tracy proves to be an unloved sweater in a rack of fluoro V-necks. Before she – inevitably – picks up the phone to dial Brooke, Tracy’s experience of New York life is lonely and deeply underwhelming (there’s the relatable part).

Tracy’s life perks up when she does finally catch up with her older-not-quite-sister (Tracy’s mum is about to marry Brooke’s dad), quickly fashioning this lively young(ish) woman into a mentor, friend and fictional figure alike. Tracy’s a writer, you see – or she wants to be – and she swiftly crafts her exhilarating experiences with Brooke into a short story, written with the kind of ambitious but self-conscious prose that you’d expect from an erudite, introverted eighteen year-old. What makes Mistress America so great is that this mythologisation of the mundane isn’t restricted to Tracy alone. It quickly becomes apparent that Brooke has also carefully crafted her persona – the carefree, enthusiastic polymath who taught herself the meaning of “auto-didact” – and, crucially, Baumbach has directed a film that revels in its own artificiality while subtly deconstructing it.

If the iPhone models are anything to go by, the film is set a couple years ago, but its New York scenes draw on the resonance of a couple decades ago, assuming the fuzzy tenor of a loose eighties comedy. When the action shifts to Connecticut – the culmination of a series of complications not worth elaborating upon – we’re instead drawn into a screwball farce, the camera navigating a spacious mansion like we’re in a Lubitsch film as characters trade “old-timey insults” like we’re in a Hawks film. It’s sharp, breezy, funny (and perfectly blocked) but also kind of dissatisfying, seemingly betraying the sense of verisimilitude accumulated in our first quarter hour with Tracy.

I’d argue that’s the point. Earlier in the film, Tracy’s given a note on one of her short stories – “the middle seems fake” – that signals precisely where we’re headed. Baumbach and Gerwig’s screenplay continues to exaggerate the snappy artificiality of the dialogue until it snaps, and we’re left with an awkward vacuum (and a fair bit of yelling). Tracy and Brooke are two ends of a coming-of-age continuum; at one end, a fiction is just being written, while at the other it’s falling apart. The screwball affectations are as entertaining to the audience as Brooke’s larger-than-life personality is captivating to Tracy, but the transience of each is assured. These are short stories for a reason.