This comes from having experienced this only too closely. This is the mental control that she has over those who serve her. She is very successful at dominating quite successfully without ever touching a whip, chain or clothespin. Rightfully so, she calls them props. For her, the mind that she possesses can sting or feel better than any instrument of torture that she could hold in her hands.
Mistress can seduce a submissive to stretch limits, and never has to coerce.
A simple suggestion that the submissive try something, which seems totally repulsive will eventually worm their way into the mind. Gradually the submissive thinks maybe they could do it, until finally getting to the point where they obsess about it, pleading with Mistress Karen Leigh to try it. As I said, I speak from experience on this point. . In simplistic terms, Mistress Karen Leigh uses emotions as a medium of sexual expressions. She employs inhibitions and emotional buttons, turning the mind into an erotic playground.