Lady Shay was out to degrade this guy and she did it with her dirty feet. The mistress forced the guy to lick her feet and even the soles of her sandals. The mistress knew that both her feet and her sandals smelled badly but she did not care. He had to do it according to how she had instructed him and that is how she exerted her dominance.
Lady Shay felt that this guy owed her an apology over remarks he had made about her. She did not see the apology coming so she forced it out of him. She did this by forcing the guy to lick her socks and her dirty feet. She humiliated him and enjoyed doing so at his expense. He finally apologized but he had been humiliated as well. She let him go satisfied she had achieved her goal.