Lady Scarlet had asked this guy a question but she did not like the answer he gave her. She was disappointed in him and she had to ensure that he gave her the correct answer. That is why she went out of her way to trample the guy and make him feel pain. The pain he felt made him rethink what he had told her and he gave her the truth.
Lady Scarlet had a new slave and she wanted to find out how good he was at his job. So she asked him to lick her boots and she graded him. He was average in his foot worship and she wanted great. So she told him he had to be careful as she was going to train him and it would be a one time training. He had to sharp as she would not repeat herself.