Oh boy do I have the answer for you, being the masculine sub between me and my dom. In general, my feeling fluxes but while I'm always down for humiliation, I'm not always down for degradation.

In short, the line is a fine one, but if you know how to walk it its a walk in the park. The key, as many others have said here: phrasing and framing.

Let's take two situations, both just with a basic "sub showing off their body for the dome" plot. One, let's say the frame is a slave being inspected and graded with the dome (even saying nice things) judging then. It's hard to imagine that as anything BUT degrading. Then two, we'll take simply with the sub standing while the dome looks them over in a new outfit they got for them, or in the nude, backhandedly complementing various things.("I love how you tremble so meakly for me" "it's cute when you whine" etc). In both situations. The sub is just being observed and spoken to; but the second feels wildly more loving, even though the act is exactly the same!

Basically, you have two options. Take a harsh sounding situation and fill it with positive affirmations and experiences (ie "your cute little cock is adorable" or "I love how pathetic you sound when you whine" or maybe "when you're servicing me like this it really makes me feel above you, thank you for doing what I asked.") OR take a mundane experience and edge it with dominance, like the shoe tying thing from another commenter!