I’m not sure I agree with this 100%, but interesting to think about. Namely, the twitter representation should be different. I’m not sure how I would express it, but I don’t think the little kid does the job. Maybe someone standing on a pedestal with the media standing around and worshiping. Unfortunately I found this on Image Shack so I cannot give original credit.
Click to enlarge.

Facebook isn’t mom-enough.
Twitter isn’t self-centered enough.
Myspace isn’t toolbag/guido enough.
Wikipedia is Harry Potter for some reason.
DeviantArt is pretty accurate, but I think a furry is more fitting.
YouTube is full of hobos?
And there’s no way to characterize Google users.
You managed to put words to what I couldn’t express. So true.
Maybe this is pictures of the intended audiences of each.
Really the picture does do a good job of representing the Internet as a whole: mostly dudes and drawn by a Japanese person.
And they won’t look you in the eye.