Well, I can only speak from personal experience here, but it happens to both guys and girls that I know - moreso girls as they do it more often.
Now, I know girls who aren't geeks who look geeky and try to act and sound geeky because they legitimately want to start getting into being a geek. I, and everyone I know, am/is fine with that, and help them on their way to geekdom. We do the same for guys heading down that path.
When girls - or guys [Though as stated, in my personal experience it is more often girls] - grab a pair of glasses, shove them on and go "OMG, NERD SELFIES" like my sister will, I will call them out on not being a nerd. They know their not nerds. They're not trying to be nerds. They're attempting to get a laugh by putting on a classic symbol used to represent nerds, then calling themselves nerds online to get 'lols', 'likes' and other crap online. This is the only reason they do it. They have no interest in being a nerd, and five minutes later they'll be back to themselves, however it is fun to make yourself a mockery of a nerd and take pictures of yourself doing it apparently.
And yes, some guys I know do this too. Though, rather than 5 minutes and 20 selfies later before they calm down, it'll usually take them 30 seconds and being hit on the back of the head, or punched in the arm, by one of their friends for them to drop the act and get back to normal life.
Really I have no problem with people who want to be geeks but aren't quite there yet, who legitimately consider themselves geeks despite not being as geeky as my friends or I, or other people that at least show some respect for the geek title. I do have a problem with those who use it as an excuse to take slutty pictures of themselves with glasses on for a laugh, before going on to say how 'gay' anyone who is actually into that stuff is. Personally, its those kinds of people that I will generally think of when that meme is posted, as in my experience they're more that type of person.