This 6 years old mare had difficulty with her young rider in executing flying changes. I tried to explain to her and show her the importance of leg yielding in order to teach a young horse the flying change. The trot I do at the beginning should be more forward and rythmic which is not the case in the movie. This is a small ring so the corner arrives pretty fast but the main issue is to ask one or more strides of leg yielding to the opposite side so that the horse has a bent to the new direction and puts more weight on the outside hind which is the first leg to ask the canter for the new lead (to the right in this case)
Of course we taught her in advance leg yielding at the walk and trot before asking in the canter. This student also had fears in jumping which she got over and now having fun with her horse.