Directed by Sarah Polley. Starring Michelle Williams, Seth Rogen, Sarah Silverman, Luke Kirby 16 cert, Cineworld/IFI/Light House, Dublin, 116 min

SHE LOOKS sorta like Michelle Williams. But what’s that thing on her face? What now? A smile? Ms Williams, an actor who is rarely mistaken for Goldie Hawn, finally gets a shot at levity in Sarah Polley’s deceptively sunny morality play, just before she’s obliged to revert back to her familiar miserablist tropes.

At times, Williams’s Margot could indeed pass for a romcom heroine. Our girl is a happily married aspiring writer when she bumps into rickshaw jockey Daniel (Luke Kirby), a cheeky sod who annoys and intrigues her in equal measure. Their chance encounter is extended when it transpires – in a shock movie coincidence – that Daniel and Margot live across the street from one another. Will chemistry lure her away from Lou (Seth Rogen), her cuddly, chicken- recipe writing husband?

The set-up says Jennifer Aniston but writer-director Sarah Polley’s treatment screams Liv Ullman. Following on from her surgically precise, unblinking Alzheimer’s drama Away From Her, the actor-turned-filmmaker makes brilliant use of naturalistic patter and observational beats.

Polley’s profound screenplay provides a steady drip feed of double meanings. Early on, Margot unwittingly nails her own shortcomings when she appears in an unnecessary wheelchair at the airport. She doesn’t like transition periods or being alone, she explains. The remarks dangle like Damocles over the picture.

Dramatic ironies pile up: Williams, fresh from My Week with Marilyn, adopts a creepy baby-doll voice to deliver sadistic sweet nothings to her spouse at home while establishing a similar series of couple in-jokes elsewhere. Her respective foils are excellent: Kirby is winningly brash, Rogen slyly low-key.

Polley repeatedly deploys picturesque pointers from romantic drama (gazing at the lighthouse, walks by the beach, lovely interiors) then blows them

to smithereens. Unhappily, her astute, ambiguous script is undone by the details.

Luc Montpellier’s camera bathes every scene with an eerie, midday haze, but even this flourish can’t disguise the unreality of the principal’s entropic world. Their swish, bohemian Toronto lifestyles are at odds with the street-smart material. The postal code offers a riot of Cool Canada snapshots, but the plush surroundings make Friends look like Serpico.

An otherwise wounding closing montage set to Leonard Cohen’s title song leaves you thinking: how on earth can they afford all this furniture?