I have to bring a little disagreement to the proceedings here. (sorry
I'd say it's what's on the bones, not the actual bones (nice as they are) that is the attraction for me. But I tend to be a little different.
A wonderful video analysis though. Very thorough. It's along the same lines, but more in depth as the stick figure tennis tips I put up. A stick figure, or in this case a skeleton shows a lot more of the inner workings of the stroke.
They've done a much better job of presentation as well as just using the skeleton to show as much about what makes the shot as possible. I used a stick figure to illustrate a small aspect of a shot.