Press on the FrangoCamera toolbar to see the animation menu items.
Mirroring is a sub-option for Image scrolling. If you select Image scrolling AND mirroring then, when the original image reaches the edge, it is mirrored to ensure the frango animation continues smoothly with no nasty discontinuities.
There are shortcuts to select these options as well.
A two-finger press on the original picture toggles Image scrolling, a two-finger press on the frango image toggles Lens scrolling, a one-finger press on the frango image selects morphing. During morphing, if you keep your finger on the frango image it will continue morphing until you lift your finger. Finally, one-finger double-tap on the frango image turns off whatever animations are running. Of course you can only have one of the animation options live at a time!