You're gonna show me a picture of foot stuff, and not have foot stuff in the tags? That's a violation right there.
Femdom can inherently have foot-domination.
This is FemDom(-ination)?
Shouldn't this instead be referred to as FemSad(-ism)?
This thing has always confused me. Along with how people keep confusing Horror with Gore, like seriously?
Your confusion stems from not being familiar with the whole range of what femdom refers to.
Femdom can contain D/s (domination/submission) and S/m (sadism/masochism), in addition to many other elements.
While femdom as a dynamic can cover more than just bdsm, a minimal, functional definition of femdom (female domination) can be: bdsm where the female sex is on top. Also femdom has a range from relatively soft to extreme, on the more extreme end of femdom, there are more elements of sadism.
A dominant female can also be a sadist to various degrees (they usually do go together, at minimum are not mutually exclusive), a submissive can also be a masochist to various degrees. Therefore, a femdom game can freely pick to include or not elements of S/m, just as its polar opposite, maledom can include S/m.