I think he exaggerated the movements for didactic reasons, so you clearly understand what he means.
This is really one of the best video I have seen on paddling, clearly demonstrating the importance of the 3 points a lot of people forget. Blade digs deeps, shaft vertical, exit at the feet.
His (Sam Ross) site has other good vids and tips:
www.sam-ross.co.uk/ His youtube playlist for SUP
www.youtube.com/playlist?list=PLP7KGVZy0gFSUxNLscqB1vS5wzYfQuTnk PS: Of course, his paddle shaft is too long, but I guess again it makes for explicit videos: once you see the "stacking of shoulders", you will remember what this mean, which is not so clear with other vids.