It is impossible to completely zoom out pictures in photos app like in iOS6. When you open a picture you see a zoomed version, not the full version, in iOS 6 you could zoom out by simply pinching in the picture. In iOS 7 if you zoom out a picture it closes to the camera roll. You can see the full version of the picture if you hold it pinched, but you are never able to see the full version leaving it steady. This is ANNOYING! iPhone camera sensor isn't as wide as any iphone's display, so you are losing a lot of the image when you display it in photos app. Jut try it!