Thanks Lolita, this is a really thought-provoking thread.
No one should ever feel obligated to post pictures of themselves on the internet, as there can be no reasonable expectation of privacy. Circumstances may require some degree of caution on the part of individuals in order to assure their anonymity.
OK, enough of the disclaimer.
My list of reasons for posting a picture is as follows:
1. Sharing the joy. I'm not the prettiest here, by any means. But I'm happy with who I am, and wish to share that happiness with others who come here.
2. Encouragement. If posting my picture makes anyone else more comfortable with posting their own, we all benefit.
3. Friendliness. This is the only forum to which I belong. I absolutely love the ambiance and support I've found here. I'm real and approachable, and feel a visible image "puts a face with the name".
4. Solidarity. We each enjoy CD'ing in our own way. I'm almost always dressed en femme when reading or posting, and imagine many others are, too. Even if they're not, that's my mental impression. I think of myself as a girl, and believe I'm interacting with other girls. That's why I come here! And I want others to see me as one, as well.
Now if only I had a decent camera, I'd update my profile/avatar pic. You can only do so much with a cellphone!