What it's for: Power Fade
Ben Hogan's finish (black and white photo) is the perfect one to copy for a fade: His left palm faces the target and his left forearm and shaft form the corner of a picture frame tilted slightly on its side. To hit a controlled fade, the heel of the club needs to stay ahead of the toe.
By creating the frame, you delay the rotation of your left forearm and the clubface just enough to prevent the toe from passing the heel early, leaving the face slightly open at impact.
If you turn the club over too soon, you definitely will hook or draw the ball. Practice this move in your bedroom in front of a mirror. You don't even need a club. Just swing to the finish, and if you can consistently make a picture frame with your left arm and elbow, you'll have no trouble fading the ball.