There is nothing to learn from shadow footage of pushing. It is a push.
1) There are no mechanics to perfect. Again, it is a push.
2) What you do without the ball will not be what you do when you have to adjust to the spin on the ball so a shadow video of pushing is really completely pointless.
3) A large part of pushing is also how you footwork to get low and over the table so you are taking the ball where you want to. But the stroke is simply putting the racket out and gently pushing forward. No technical complications are part of the ACTUAL STROKE.
4) One of the actual important factors about a push is how you read the spin that is coming at you and adjust the angle of the racket to the kind and amount of incoming spin.
5) Another important factor in a push is how relaxed your grip is and whether you soften your grip, keep it how it is or firm your grip AT IMPACT. Different grip pressures will give different results: more spin, less spin.
6) Another important factor in a push is how you touch the ball, softer, more forcefully, more directly, more tangentially.
3-6 CANNOT be seen in shadow pushes. It is just that simple. You would be wasting your time and everyone else's.....well, except that a video of of you doing shadow pushes AGAIN would give EVERYONE a good LAUGH, AGAIN.
Viewing shadow strokes to correct form is of limited use in any instance. Where shadow strokes are useful is to try and get the form of a more complicated stroke or footwork pattern into muscle memory. They are about repetition and they are for YOU. NOT FOR SOMEONE ELSE TO SEE YOUR FORM. Unless the someone else is your coach and your coach is seeing 30 seconds of shadow work in person to correct things so you can go back to practicing shadow strokes with better form. Part of the idea is that, if you got 10,000 reps of a FH stroke in front of a mirror, YOUR FORM WOULD IMPROVE. However, 10,000 shadow pushes would likely not improve your push. That work needs to be done with the ball AND VARIED SPIN.
The mirror would also be for you to see what you are doing. Not for other people. But with a push, seeing the form would not really help because you still would not be seeing how you adjust to the ball which is the real issue on form. Video of you trying to push on serve return while the server is varying the spin, watching that WOULD BE USEFUL. You getting footage of you returning serves with varied spin and watching, week by week, consistently, as you adjust and then see what the adjustments you have made actually look like, that would be helpful to you.
So, in a stroke like a FH where the timing of when your hips pop or your forearm snaps, or your wrist whips, or any number of other things that all have to happen in a complex sequence that CAN BE practiced TO A LIMITED EXTENT without a ball, then shadow strokes make sense. BUT ONLY FOR YOU GETTING EXTRA REPS. Not for showing other people your form.
Even with your FH shadow strokes, what you showed us was SOOOOOOOOOOOOOOO different from your actual FH stroke and SOOOOOOOOO much worse than your actual stroke while hitting the ball because your internal image of what you thought you were trying to do was SOOOOOO incredibly off the mark, that what you were doing as shadow FH strokes FOR THE CAMERA, was also pointless and ridiculous.
Show real footage of pushes or don't waste the time.
