Interesting question... had not thought about it. BTW... I don't teach "Keep your head down"*. You'll get hurt if you do. The head must come up and out naturally, to allow the body to complete the unwinding freely without restriction. Actually, my face on most shots, will look like I'm looking ahead of the ball. This is because I don't look at the ball (pre-se). My face is on the way out, anticipating an accelerated rotation to face the target. I don't want my head to restrict my body's unwinding*. What I mean is, I'm looking down in the general area of the ball, but my eyes are not focused on anything. I'm visualizing in my "minds eye" how I want my body to move. There is no need to look at the ball as if you were going to hit at something**. The ball is just in the way as we turn. I don't even think about my head saying still. As long as I keep 60% (or more) weight forward on the backswing, I don't have to worry about sliding forward off the ball. This gives confidence and I guess my face just starts out because there is no need to stay behind. * I know I have lesson videos that tell golfers to "stay behind" until the back shoulder meets their chin, then let the head come up. This is help for golfers that are moving off the ball too soon. ** The golf swing (in my method), is not a "hand/eye" coordination move. We let the Large Muscles control the arms/club. We don't hit "at"... we turn "through".
Move Less ... Get Good! DUPLESSISGOLF