It’s impossible to describe how phenomenally good a job Maslany did with these characters. Like, it wasn’t just that she played every one of these characters so genuinely and distinctly that you forgot they were the same actress. It was also that the characters, being clones, would deceive people by playing each other.
Alison would be on the screen, and you’d be like, “that’s Alison”. Then Sarah would be on the screen, and you’d be like, “that’s Sarah”. Then someone who looked exactly like Sarah would be on the screen, and you’d be like, “Oh, Alison is pretending to be Sarah.” And some of the clones were better at pretending to be each other than other clones were. And you could always tell who you were looking at and who they were trying to imitate.