Edit: Ah okay, it wasn't playing properly when I first saw it. Now it is.

MisterJuice said:

I'm not exactly sure what's going on here...I think it's implied masturbation with the vacuum? However I might be wrong, and apologies if I am.

It's a bondage thing.

It's not necessarily masturbation in itself, but it is a fetish thing (it's a specific kind of bondage, as I understand it); vacuum bed is a subset.

Yeah sorry folks, for me when I first saw this it was at least broken on my end, so it was only a still image of the first frame. Where it was entirely unclear what was happening, and I thought she was hiding the vacuum to masturbate with it or something. Now that the gif is working it makes sense.