Lady Scarlet did not like how this elderly employee liked to use the age card to get out of situations and issues he had brought on himself. He would make a mistake and then pull out the age card when it suited him. She was fed up with that as he seemed to think that he could not take responsibility for anything. And that is how she used her dirty feet to punish him and tell him it would not happen again.
Lady Scarlet is the sort of girl who loves to use humiliating ways to punish whoever she does not like. The mistress today wanted to use her high heels to dominate and to humiliate so she got her slave to lick her high heels. And she did not care that he was elderly or that he was degraded by doing so. He had to do as she instructed and that was final.