I chose mine because it was a good design and it was for low points. I hardly ever see anyone who has the same as mine. I think it also kind of shows I'm not some nerd who stays up on AG all night spamming game comments and rating games that I haven't played for points.
Beams of light are about as literal (or visual, to be correct?) as a representation of my chosen name can get. I didn't know there was a such avatar when registering, so that's a lucky coincidence.