Mistress Nica and her friend felt that this guy was a loser and that he had to learn his lesson the hard way. So the mistresses used their high heels to punish the guy and make him regret what he had done. The mistresses were not in the mood to forgive him so they did not listen to his cries of pain. They ignored him and laughed at him as they punished him.
This slave was asked to care for mistress Nica and her friend's ponies. But he did not do a good job of it and the mistresses chose to punish him. He was made to lie on straw and hay while he was naked and the mistresses whipped him and trampled him to send a message to him. That is how he learned to do his work properly and avoid being punished.