That is true to a bigger or lesser extent. There is a huge range of how much people represent themselves here, from a tiny percentage to a bigger one. Everybody has their own preference.
As for me, whatever physical part of me you see is real. Personally, I only get the thrill of communicating with someone when I know that someone here is communicating with that part of me which is real. I'd rather be an 'unwanted myself', than be a hit using another perfect person's face/anatomy. If I want to go all the way visually anonymous, I would take a picture of a dog, bear, landscape, cartoon or whatever, so that some people may not mistake somebody else's face/physique for mine.
I'm not stating what is wrong or right here, just how I personally prefer it.