Not positive about the reasoning, but skeet are falling targets and in the international game you are not or were not allowed to move the gun away from your hip until after the bird was visible. Not sure about present rules, there have probably been some rule changes since I shot any of it in a registered shoot. The relationship between pitch and POI are almost nuance, sorta, but they do interplay when mounting a gun quickly from a low gun position .. at least I have proven to myself that it does, for me. Pre-mounted ? all POI statements are negated, but you could still get smacked in the cheek if you cheek the gun hard and it has too much down pitch. I've been there, several times.