This is the highest level of dressage known as "freestyle".
Dressage is complicated, all about a horse's back, shoulders, and haunches. Flexibility, strength, and response to commands by the rider you cannot see. Dressage comes from war. The need to command a war horse so oncoming soldiers cannot see which way you will go, or when you make your move to go in a direction. They meant for their war horses to last and last. It is weight on your hips, a squeeze on your reins, a touch of a spur.
My Dad was in the horse cavalry, learned stuff, taught me stuff. My Dad got on my horse, Brown, and asked for his grand kid to be put into his lap. That was my niece. He was 80. My niece was 4. Brown was perfect.