If you want your 2 pictures to appear to morph/change from one to another like Chris's avatar. (I hope he doesnt mind being my example)
Example:
Unless you draw each 'frame' of the transition on your own and put them together (as demonstrated in previous post), you'll require a software that will perform that process (usually called "Morphing") but might be referred to as a transition as well.
I havent done alot with "morphing" so someone would have to pick up on that if possible.
