Princess Serena was angered by the fact that her slave did not know how to do laundry. So she used her socks to punish him. That was meant to teach him how to do laundry. She choked him with her socks and she had him smell them besides licking them. She had made sure they were smelly first before she let him lick and smell them. It worked and he had to learn to do laundry in order to avoid such punishments.