There's nothing about this video that isn't outright, explicitly sexual, and at least as far down as we're able to see, she's fully clothed the entire time.
This is exactly what a certain part of my brain starts thinking about, anytime I see any woman, whom I already find myself thinking about sexually anyway, sneeze, or need to or try to; or if she yawns in front of me, or (and part of me really hates to admit this because I feel horrible about it) if I should have the displeasure of seeing her physical pain tolerance become exceeded to any extent worth mentioning. The last thing I just mentioned is not something that causes me to think that way while it's happening, fwiw; I physically cannot become aroused in the presence of anyone experiencing severe pain, unless said person is literally a masochist who's feeling that way on purpose because they get off on it, in which case I also get off on that, and in which case that's different and I don't feel at all bad about it. Anyway, yeah. You're right. The kinds of faces, noises, etc. that people make involuntarily while masturbating, are, unsurprisingly, quite similar to other involuntary expressions of other physical tensions also perceived extremely, including but not limited to trying to sneeze.