Mistress Liza felt that she needed to humiliate this guy in a non painful way. So she had to change tact from what she was used to and she used her joi fetish to do so. The mistress had to make sure that she degraded and tortured this loser which is what she did. He never messed up as she degraded him with her jerk off instructions which were geared to make him feel humiliated.
Mistress Liza was of the opinion that she had to dominate this loser and do it with her jerk off instructions. She did not want to let the guy get away with what he had done. The mistress showed him what she wanted him to do and she then sat back and watched how he did it. To make it easier for him, she even teased him a little and it worked.
Mistress Liza always got her colleague to do her some major favors and when he was down, she felt that she had to lift his spirits up. She chose to do it with some naughtiness and that is how she got him to jerk off. He had to do it to her instructions and it was a lot of fun for her as well as for him. The mistress loved how he had enjoyed it.