It's acting more like a dog than a cow. And there are many other videos of horses playing and doing tricks like dogs can. My opinion of horses greatly improved. Thinking about it, I shouldn't have found it surprising. Horses are herd/pack animals like dogs, so they naturally have social skills, and despite being herbivores they are still mammals, so their body language is at least somewhat similar to humans. And also like dogs, horses have been domesticated to work closely with humans. Most other domesticated animals are either solitary, or not required to work directly with humans. I think any domesticated mammal with both those properties will likely read human emotions. Even though the dog has the advantage of being a carnivore so it is more similar to humans, and being required to work more independently than the horse, putting more selection pressure on its communication skills, the horse still far exceeds popular animals like the cat in its ability to communicate with humans. If the dog is "man's best friend", I think the horse can be "man's second best friend".
Dudley looks a little smarter and more active than cows I see locally, but not nearly as much as a horse. Most of his "playing" looks more like scratching/rubbing type behavior, the same as you see with motorized cow brushes.
Probably not a coincidence that they're also one of the relatively few domesticated animals (https://en.wikipedia.org/wiki/List_of_domesticated_animals).