All of us have seen nervous, frustrated, and angry horses but what you are going to watch in this video is not something that happens very often. The horse seems to be agitated as the ceremony of the guard change is taking place.
You see it constantly hitting the concrete post and the rider does a very good job in keeping it under control. Maybe this horse just wants to play with his friends and he is throwing a little temper tantrum.
He is probably a little anxious to join the others and this is not unusual but amusing for a serious situation. He seems a little stressed just to join the herd as horses are herd bound but of course the rider is appreciated for being calm, patient, and showing real professionalism. Watch the video!