Oh, ok, but can you tell me?
Viewing post in Mirror Hall jam comments
firstly, go through the mirror and press the button, then unfreeze and freeze, so that the clone ends up on the other button (the button in the reflection is fake)
Secondly, press the button, and you will have 5 seconds to reach the exit (you can run by holding shift), the gap is small enough to be able to jump over it, while running. Go through the exit, and you're done!