When this mistress noticed that her slave was slow, she felt that she had to torture him in a way that he had never been before. She had given him some time to adjust and to change but he did not which meant that she had to do something about it. She made her socks smelly and she used them to dominate him. He was trampled, choked and had to lick the smelly socks.
Mistress Zephy caught this guy doing something irresponsible and she knew that the best thing to do to him was to humiliate him for his irresponsibility so that he learned to be an upright and responsible citizen and adult. Since it was the first time she had caught him doing it, she punished him with her feet because it was a light punishment. He licked her feet and was humiliated but there was no pain involved.
This mistress had to do something she had never done before and that was to punish this slave by making him lick her feet clean. She was disappointed in him and she felt that it was important for him to learn that he could not escape accountability for his actions. And so she summoned him and she made him lick her feet until they were clean. She warned him of worse if she saw no change in him.
Mistress Zephy wanted to test her slave and she did not waste any time in doing it. The mistress wanted to find out how well her slave took instructions and that is why she chose to make him lick and smell her stinky socks. And she told him how to do it and watched closely to see how he carried out those instructions. And she loved the fact that he was good at following instructions.