Flipanim has this glitch, and it happens whenever you see an animation with a white background, and there is tweening involved, on the following page. It basically shows the frame going from white to black to white to black, and the speed of that depends of the fps of the animation. I'm worried that this will effect epileptic people. For, proof of what I'm talking about, go follow @Animateskiller (this is also a shoutout), and look on his page and you might see it. But when you click on the animation, it will be normal. I don't know if this happens for every device or browser, though.