Somewhere along the line a coach probably told you to "squeeze your glutes at the top".
So you, trying to be a great client who follows instructions, end up doing the move you see in the picture on the left.
The problems are:
Back is hyperextended
Weight is BEHIND you and no longer over your center of gravity
Core is now stretched, losing all control and bracing
I hate to break it to you, but this ain't doing anything for your booty growth and is only going to put your lower back in a world of hurt!
INSTEAD - Try standing glute flexes, film yourself, and watch your video back.
Practice until you can achieve squeezing your glutes without completely bending your entire body. This is the form you want to incorporate in your squats.