When this guy tried to steal from this mistress, he did not count on getting caught. He did not have a plan for what would happen if his plan A failed. So she had to find a way to deal with him and she did so by smothering him with her feet. She did it over hours and made sure every inch of his body was in pain. He never stole again.
Mistress Gaia hates lazy people and when she realized that this one was lazy as well, she had to punish him. He was new and she had not noticed his laziness before but now that she had, she had to make sure he was crushed and trampled to make him change for the better. And he had no choice as she promised worse punishments to him if he did not change.