Nicholas has worked with this Fourth Level pair before.  As they walk in the warm up he already requires that the rider pay attention to details- making sure he stretches down and out, and how he goes off the bit when they change directions.  In the trot he insists that she position the neck in a useful way by giving him consequences when he changes the shape, and then reward him for the correct frame.  They get lovely overtracking and stretch in the trot.  Nicholas works on the walk pirouettes next, keeping them forward and small.  Watch for excellent tips on the pirouettes.