Thought these images would help folks understand "Normal" to the club at impact.
Normal means PERPENDICULAR. In the case of the swing, it means PERPENDICULAR to the SWING ARC.
Here is some pics of Ben Hogan from 1948 & 1955 to some the difference between force perfectly (or nearly perfectly) NORMAL to the clubhead, and force somewhat not NORMAL do to some force across the shaft:
"Normal Force" is perpendicular to the swing arc. In my opinion, it is obvious that in the Power Golf swing:
He is not as "Normal" to the clubhead as in the Life Magazine swing: