Support for pictures on moods is coming soon. There are two sets of mood icon sets under development, and I hope more users will submit new mood themes. The current ones are: classic (one I'm planning on finishing some time) and nolegs (from user nolegs). After I get a set of mood icons from somebody, I then have to map them to the list of moods. In the future, you'll be able to select your mood theme, and then when you use a server-supported mood, the corresponding picture from your mood theme will also show up.
Please, send in mood pictures! (but only if you made them yourself... don't steal from other people!)