This is a fantastic movie.
I believe that the power of this film stems from the fact that throughout the movie, the violent perpetrator is only seen for a few minutes in total. Yet his acts, and the consequences of his actions upon the victim, are truly brought to life.
It really gets the message across that you don't necessarily need to be physically abused to be abused, and that you don't need to see the act itself to realise someone might be in such a situation. It clearly shines a light on that fact as well, sending an awareness message to the audience.
Just excellent.