Both are an affectation. But that’s nothing bad, we do so many things for appearances, it’s pretty normal. I have a pretty big beard myself, and for no reason except that it accentuates my face very well.
It's vanity, and that's fine. But affectation supposes something fake:
'Affectation noun behaviour or speech that is not sincere'
To me that's a (negative) value judgement. And I'm defending the point that there's nothing inherently negative about vanity, unlike what's being implied by our dearest Dr.
I interpreted that as her referring to the pretense that the beards of the guys is anything but vanity, who at first try to swing words like proud tradition and sign of masculinity as justification. IIRC she even says something like "there’s nothing wrong with it I just want you to admit it".
But yeah I guess we are arguing semantics at this point because we both seem to agree on that a bit of vanity is completely fine and normal.