if you're trying to measure how high he is you need to draw the line parallel to the edge of the pipe walls, not a straight line across from the skier to the tower.
I think that was more for scoring purposes. If a person was the same height as the 20 they would get a 20 for theyre height score. That's just my guess though. It was really gay how they where anouncing that they where going over 20 feet out though cause that's just a lie it looked more like 14 or 15
actually, expn is the best thing for skiing, this even is what publicizes the sport the most and gets people from outside the ski world to actually see and enjoy the sport, stop crying.