Lady Liana felt that her message was not getting to where it was needed. She felt that the best thing to do to this guy was to use her shit to humiliate as well as to dominate. She had to make sure that the guy never ignored her message again and so she used her shit to do it. He had to eat her poo for him to get her message.
Princess Nikki was fed up with how this slave was a loser and he was not providing any value to her company. So she chose to deal with him in the best way she knew how which was to dominate and degrade him before she fired him. She went ahead to take a shit on him and force him to drink her urine and eat her shit then fired him.