Speaking only for myself, I've had a bit of a fight to calm down about my appearance-- I'm 59 and apparently more or less look it. It's been work (pretty successful recently) to not feel like a failure because I don't look like I'm 30. From what I can gather, this isn't uncommon among women, and frequently in stronger form.

Your frequency argument is relevant, but needs a bit more causality added-- the reason the pictures are so common is presumably because they're what's preferred.