Federer serve position

I messed a bit with a video clip I found at TennisOne to better understand Federer's position and alignment when serving. I copied several frames and outlined the one with the tossing arm at the top of the cycle, and extracted the position of the ball in different phases of the serve.

Take a look at the diagram and notice these reference points:

1. The lowest wind-up position corresponds to the moment when the ball is almost at the apex.
2. The tossing arm is right above the eyes, and the head is nearly horizontal and over a foot behind the hips.
   
3. The tossing arm releases the ball at just over 6'.
4. The toss is about 11' high, or 5' above Federer's head.
5. Federer lets the ball drop about two feet before hitting it. This looks like a kick second serve.
6. The racket head reaches the top of the wind-up in the position shown, just when the tossing arm is at the top of the cycle.

I tried to replicate this position in front of a mirror and realized that the head should be much farther back than what I usually do, and it really feels kicked back much farther than usual.

Here's the original clip.