Because it's a mystery. Oooooooooooooooooo :-)
But seriously, from the Polish trailer I was watching, you moved the character around and a small icon comes up when you are able to interact with the environment or when you are able to perform an action like punch someone. In one scene, the character was in a struggle and an icon popped up so you would shake the controller up and down to break free.
Outside of that, I don't know how the game is going to play but it looks gorgeous as hell. We'll find out soon enough I guess.