i saw the film in dubai international film festival yesterday and there was a Q&A session with actress Suzanne (who plays the neighbour)
i asked her about why the unique aspect ratio was used in the film
she answered :
(sorry for the poor quality)
http://www.youtube.com/watch?v=SUjqhpupTgo
Fantastic film by the way, in my top 3 of this year along with birdman and boyhood
A lot of people talk about how the aspect ratio is used to display a sense of discomfort and uneasiness but I remember hearing in an interview that Xavier Dolan picked the aspect ratio mainly for the focus of the frame. He wanted to capture the person's whole portrait and have nothing else in the background (no distractions; the sole frame would be focused on the human being). I wish I could link the interview but I can't remember which interview (watched too many haha!).
But yes when the screen opens up, what Suzanne Clement says also brings togehter another aspect of it.
Yeah, I read that too somewhere and I immediately thought: "What a hipster".
But after watching the movie last night I must take it back. It was a really interesting choice and worked on many more levels than just framing portraits.
Great film.