Victoria,
I now use a close up pic of me dressed but I can remember some of my ealier ones. I think the first was an outdoor pic with me so far away it could have been the Dalai Lama. The next was a little closer but still fairly ambiguous.
I guess the thinking was if I posted something more recognisable I'd out myself to the whole world. I guess also it has to do with having a pic that looks ok. Over time my presentation has improved although you might say looking at my avitar there's still a long way to go!