On paper, this should be the perfect showcase for Amy Schumer: the title is taken from that girlishly hopeful song in the 1961 musical West Side Story delivered by Natalie Wood, whose gamine image is of course so different from Schumer’s. Yet at almost every stage, Schumer’s routine is weirdly restrained and inhibited due to the film’s high concept: that she becomes an aspirational success, against all the odds. It’s a plot imperative that works against the disaster, embarrassment and cynicism integral to Amy Schumer’s comedy.

The film is written by the romcom veterans Marc Silverstein and Abby Kohn, with obvious borrowings from The Devil Wears Prada and Ugly Betty; they are making their joint feature directing debut, and Schumer has a producer credit. She plays Renee, who works in the online delivery unit of a big New York fashion brand, stuck in a dull office well away from the super-prestigious Fifth Avenue building. She is a woman who is insidiously made to feel ashamed of her bigger size by the patriarchal body-image imposed by the worlds of media and fashion, and by the impossibly slim women surrounding her at the gym. One day she hits her head during spin class and wakes up believing that she is a size zero babe and the resulting delusional aura of confidence – together with the fact that her fashion brand is trying to reach out to “ordinary” women – means she gets a top job there.

Actually, Schumer is pretty, and the casting wouldn’t work otherwise, but despite the disconnect between how she is portrayed and how she feels, she is never really abashed and there is no comic friction. In fact, it is more a parable of how celebrities like Schumer, on becoming successful, suddenly get an inkling of how beautiful people have always felt. I Feel Famous would be an alternative title.