If someone accused her of being in a video dancing, would she deny being in it?
I mean, if dancing were not something shameful, would she not just say 'yeah, we made that in school' or something?
Whoever did it, did it to make her flinch. As if it would be shameful. She flinched, and acted like it she wouldn't do that. That's why I call the behaviour 'slut shaming'.
Now that you mention it, it may not have been her denying she was in it. It may have been from someone else (who would then be the one doing the shaming)
But it doesn't matter a whole lot. You mostly don't care to understand disagreements, but to bludgeon with them.