Originally Posted by TheCheese
You can watch the entire video. It's clear he's pulling up and across the ball at contact. Watch Rafa, watch Djokovic.
If you want to describe the whole motion with biomechanical terms, that's fine, but I don't think it's a very good tool for most people who just want to play tennis well.
Are you aware that Roger Federer was taught by an Australian coach named Peter Carter who advocated hitting through the ball with a long follow through? Oscar Wegner has no connection to Federer that I'm aware of.