The trick here is a little subtle and hard to see from a distance.
What happens is that the quarterback turns back and to the right, as if he's pitching or rolling out in that direction. But he then tosses the ball over his head, backwards and to the left.
I wonder if this can be duplicated or if it's a one-off. The idea seems sound -- the defense moves in the direction the play seems to be going. If you throw the ball backwards over your head (without looking -- a timing play) they're not really going to be ready to make that interception.
I'd like to see the NY Giants try this. We can't score in the red zone, and Eli Manning tends to throw interceptions when he's aiming and looking at his receiver, so...