Once the images are loaded it doesn't flicker, if you press the +1 button a few times it flickers but when you go back with -1 everything is already loaded and it doesn't flicker.
Maybe use 'new Image().src' to preload the images?
Video and webcam flicker too.
The webcam is a hilarious example. Reminds me of this 1-dimensional video game you can play in your address bar. http://glench.com/hash/