It's no secret that cornerback is one of the hardest positions to play in football. There has to be a balance between playing physical against who you're covering, trying to break up/intercept passes and do so without getting a penalty flag thrown.
That makes positioning important for corners. In order to be able to break up a play, they need to be in the best position possible to make a clean attempt on the ball. In this scenario, that's what Moore does, finding his way to the wide receiver's hip pocket.
At the start of the play, the receiver hits a move at the top of his route to attempt to make Moore bite on a different route. He doesn't fall for it, stays patient, and runs with the receiver as he makes his break towards the middle of the field. From there on out, he's right in the hip pocket and gets his arm in between the receivers' hands to break up the pass. It looks like the throw may have been a bit behind the receiver too, but Moore is still in a position to make a play on the ball if the QB hit the receiver in the chest.
Moore's effort on display