Gio said in another thread that if you have an animation with 3 frames A, B, C and you play them in reverse, you should get C, B, A.

 

It looks like you get A, B, A instead.

 

It seems to me that it's only the first frame that's wrong, because it's always the start frame of the animation even when you play in reverse. With 4 frame you get  A, C, B, A, and if you loop a 3-frames animation you get A, B, A, C, B, A, C, B, A, ... (it's all correct except for the very first frame)