Goddess Mia wanted her slave to lick her feet and she instructed him to do it. He did not have a choice and he had to do whatever she asked him because there would be consequences if he did not do what she wanted. He had to lick her soles and she made sure he licked her bare feet, her socks and her dirty sneakers as well before he was done.
Goddess Mia wanted to get her sneakers licked and that is what she made her slave do. She did not want to discuss it and she told him point blank what she wanted to be done and he knew that he had no choice but to do it. If he did not, he would have himself to blame for what would happen to him. So he obeyed her and did it.