It's an attachment you add to your post. scroll down, you'll see it.
I'm trying to figure out how to do the avatar thingie. I'm hoping that will accept motion. All the attachments I have added to a post move. Only they don't here. Not sure if the Forum sees them as images or applets, which is what they are. I think you have to use the regular reply option, not the Quick reply.
"I totally don't know what that means, but I WHOUNT it!"
-Jessica Simpson
I know the avatar (which is added through your user CP) will allow movement, as mine does. Not sure about attachments to posts though, have never tried that.