Crushing

So I somewhat understand smothering and facesitting. Crushing eludes me. I'll do it, sure, but I'm not clear on what it does for men. Crushing/Trampling. There are vids all over YouTube of women stepping on things with bare feet and with sexy shoes, and even not so sexy shoes. Crushing toys, food, gum, whatever. It is purely psychological, and I get that because the mind is the most important part of sexual desire. What I don't get is why. I know it is sort of a power trip, but why does it evoke such desire?