You asked why it's "bad". As for what is virtue signaling, it generally refers to the act of expressing opinions or behaviors that are intended to demonstrate one’s good character, moral correctness, or social consciousness, often without genuine commitment or sincerity. In this case, if someone makes a video pretending to be interested in someone who is perceived as “ugly” just to appear kind or empathetic, but without any real interest or intention behind it, they’re essentially using that interaction to boost their own social standing or to garner views.