I'm sure you could look at any BDSM activity and situation and find a way to perceive it as involving humiliation, but that doesn't mean that what the participants are getting out of it has anything to do with that way of perceiving it. Does that make sense? I don't think it's really valid to say that an act is inherently humiliating - well, maybe for some few acts it is, but not most BDSM activities. If one person thinks that wearing a collar is humiliating but another takes pride in it, how can you say that one or the other has the "correct" view of it? It's all subjective.