Display a photo on your touch. When you turn the touch vertically and horizontally the picture changes orientation so you can still view it "upright". Now, do the same thing but as you are turning the touch, keep tapping the screen with two fingers. The trick here is to be tapping the screen when the picture is midway between changing orientation. If you do it right, the picture will stay tilted on the screen. This only affects the picture you're viewing at the time and the effect goes away when you bring up the next picture. You can also do the two-fingered enlarge thing with the tilted picture.