Mistress Zora's slave trots after her like an old donkey until she doesn't feel like walking anymore and straddles his back. Fot as long as she wants, the slave will let her ride on his back. Too bad for him that Zora is bored on his back and already has an idea how she can humiliate him further. She stops her pony and dismounts him. She makes him take off her sneakers then pushes his face into them and forces him to inhale deeply. Does that improve his ability to be a good slave pony?! Mistress Zora tries it out and lets him breathe the scent!
Lady Amber's slave will now be punished justly. She hits him over it with the crop and sits down on his back with her jeans ass. Now he will serve the mistress as a human pony whether he wants to or not! Punishment for the slave! The lady is now riding round for round on her personal human pony. That's what he get for not listening to her! Lady Amber is riding as long as she wants now!
For Angelina it's just normal to train her slaves to be a human pony during their slave training. As a young dominatrix she knows exactly how to make submissive slaves follow her orders. Just like this slave should feel honored to be allowed to serve this goddess as a pony. And when her pony can't take it anymore? Then Angelina will just make it move with some kicks!