This loser tried to scare his mistress and found that she was not scared but she was pissed. She does not like anyone to do crap like that to her and she had to teach him a lesson. She did this by slapping him to make sure he never had funny ideas like that again. To make sure he did not interfere with her punishments, she tied his hands before slapping him.
This mistress knows the best way to humiliate a slave is to make sure he is in a lot of pain. That is the language of the slave and this slave was spoken to in that language by this mistress. She forced him to lie down and she trampled him and tortured him with hard slaps. She did not want to use anything other than hard slaps but it worked just as effectively.
Lady Cruella is a cruel mistress and derives her name from torturing people sometimes for no reason. She is a sadist and enjoys it when others are in pain. If she realizes she was the cause of someone's misery, she is very happy. Today she slapped this loser and yet he had not done anything to him. She used an excuse to punish him and later pretended to apologize when she "realized" it was not her.