Mistress Annalise did not want an aggressive slave because aggression would lead to liabilities for her. There are those who preferred the aggressive type but not her. So she had to make it all change. That is why she used her shit to make him drop the aggression. She had him lick her asshole clean when he was done doing so and it worked as he became less aggressive the way she wanted.
Mistress Annalise wanted to shit on this loser and he did not have a clue about it. She teased him with her hot body and since he knew she was naughty, he thought she was interested in bedding him. But he was shocked when he found out that all she wanted was to shit on him and she did. She made sure he ate it before she chased him from her house.