A nice, sexy animation, but it could use a bit more delay between frames. It cycles too fast (on my system at least) to actually see any single frame.
Note, you can use the edit button to change the attachment and change your signature line without editing it. The code will display whatever picture you have attached to that post and will change with each edit.
Just don't ever delete the attachment, becuse you can't add an attachmetn back once it's deleted -- you can only change an existing attachment.