Quote:
"Why have one actor play your lead character when you could have two? That's the central conceit of this distinctive Canadian indie, written by the actors in question, Amy Nostbakken and Norah Sadava, and adapted from their stage play. They are both Cassandra, a disorganised woman in Toronto thrown into crisis by the death of her mother. Unlike movies with similar conceits—Luis Buñuel's That Obscure Object of Desire, for example, where two actors alternated in a role—Mouthpiece keeps both women on screen at all times. As a reflection of a fractured mental state, it's an effective device, although the relationship is not sharply defined."
-- Steve Rose

Source:
Rose, Steve. "Mouthpiece review—double the drama in doppelganger story." Review of Mouthpiece. Guardian, March 10, 2021.