Easter egg?
Weird function I found while playing around in photos. When you're viewing an image start pinching to minimize and the other pictures start to fade in in the background. The pic you still have pinched with two fingers can be twisted and turned.
Thought this was pretty interesting. Apologies if it was mentioned before.
That's also in iOS 6. Just double checked my iPad which is still on 6.1.3 and I thought when I read your post that I had done that twisty thing before. It would be a really cool feature if it would stop in the position you left it, as when wanting to show someone a photo who is sitting opposite from you.