Unless there's something quite absurd in their BH avatar pic (I will leave examples to your imagination so as to not single anyone out), then no. But if it's very show-offish or kind of offensive, I think, "Pfft, tosser."
On FB I do. Mostly judge them as "loves herself," or whatever. Usually not by FB profile pic alone though... more if they post a thousand pics a week of themselves in a bikini or whatever.