Horses are truly beautiful, intelligent creatures. That being said: they can be evil to the core. Some horses will stop at nothing to thwart your attempt to make a good photograph, and believe me, they know exactly what they're doing.
You see, nothing looks more majestic than a well groomed horse, with ears up, and fully alert. On the other hand, nothing looks more pathetic than a horse with its ears askew, and eyes drooping. So, the photographer and crew engage in all sorts of humiliating nonsense trying to trick the horse to attention (which can be tiring when you have a hundred images to shoot). To the casual observer of this process, there would be little doubt as to which species was more intelligent.