Princess Serena wanted to make sure that her slave was not going to misbehave. She did not want to be punishing him every other day so she punished him once and let it be a reminder to her of what she is capable of. She used her sneakers to do it. She told him she had more in store in case he ever messed with her. She made him lick the soles of her shoes then let him go.
Madame Marissa wanted her slave to learn the virtues of being well disciplined. She punished him because of the way he acted and how indisciplined he was. She was pissed when she learned that he lied to her a lot. She had to make sure that her slave would never do it again so she gave him a punishment that befit his status as her slave before she left him go.