Idk if there's a reliable psychological signal there, but to me it looks like someone performing a chore. Bored but compelled, like...an obsessive eater shoveling it in even if they don't like it much but can't conceive of not eating whatever is there. Or to put it into a completely different context, like you might do at the gym when you're not enjoying it, not exactly pushing your hardest and rebelling internally but just trying to check the box for reps the trainer told you to do. Sort of a "God dammit, I have to do this." But in her case, not doing it for a good goal and not even aware that she really wants to stop bc the overriding habit and desire means she doesn't want to stop. Iow, her body doesn't want it but she is totally out of touch/disregarding that.
*caveat: that's based on those stills only. If before and after that it was the orgasmic eyeroll, then I retract the read!