I hate getting my picture taken, and would not normally attempt such a thing as a self portrait, but getting a new camera and being a member of a site called Fujimugs, without a 'mugshot' spurred me to have a go a couple of years ago. It being digital, nobody would see it if I didn't like it, so no feelings hurt, no embarrassment, and I'm in control.
I went the picture in the mirror route, as trying to set up something with a tripod seemed too pre-conceived (plus I had no ideas, and wouldn't feel comfortable doing a setup scene) and frankly it was too hard to attempt alone.
As to why I did it? I wanted to conform to the aims of one of the sites I visit to be a community, and it's always nice when there is a face behind the picture or post. Avatars are great, and I use one with my posts on a lot of sites, rather than an actual picture, but on most sites (as there is here) there will eventually be a thread with the subject 'What do you look like?', giving people the opportunity to show the real person behind the posts, or not. I'd like to be involved, or have the choice to be involved with such a thread.
The style I chose, with a camera covering half of my face probably showed the underlying dislike of seeing pictures of myself. I mean half the picture was good, it had the camera in it,

but also it has to be said, the desire to be seen I think. There may be other meanings, but as with anything, if you analyse things too much, you start talking sh*t quite quickly. The art world is full of 'bullsh*tters', when the most important question of 'art' or anything in my opinion, is do you like it or not. Not that I'm saying my picture was art, but I liked the picture I took, so the picture could be shown to other people.
That is one of the great things about digital cameras, you can practise such things a lot easier than if you you had to use film.