Madame Marissa has a gorgeous ass and she knows it. This guy tried to spank her thinking that she would be flattered and would take it as a flirting gesture. But she did not and she was offended by what he did. She was so pissed at him that she had to degrade him and she did this with her hiking boots. He was shocked and humiliated by it and he regretted what happened.
While madame Marissa made her slave lick her boots, she felt that it was not enough despite it being humiliating to him. She felt that she needed to do more to dominate as well as humiliate him and that is why she chose to turn him into a human ashtray. That was painful as it was humiliating and cumulatively, she felt that he had learned his lesson and she let him go.
Madame Marissa had a lazy farmhand and she knew that the best way to deal with him was to use her hiking boots to trample him. That is exactly what she did to him and she made sure that there was a lot of pain on his part. The lazy farmhand learned never to be lazy again as he did not want to feel that kind of pain ever again.