Pushup

On the push-up, does the scapula protract completely during the concentric movement and retract during the eccentric movement?

Yes 

LateStarter@46 said:

Yes 

Awesome. I just wanted to make sure that's wwhat I was seeing in the video. Thank you

When doing push-ups this way, is it supposed to focus mostly on the shoulders? Before when I did push-ups, I only felt them work my chest, now I feel slight chest, some tri and biceps, and mostly in scapula and shoulders.

No, not full retraction, these are not scap shrugs. Bottom of a PPP for example, I'm still trying to protract. Bent arm planche, still trying to protract. Can I get to full protraction? No. But I don't retract.

Adding protraction at the top = good idea, good habit. Locking in that protraction as much as possible to keep your body hollow and tight from shoulders to toes whilst you put out pushups = good reps, good habits for PPP, pl leans, etc. Actively retracting = body sagging, emphasis away from working body parts, disconnect in power to the arms IME.