Recently I visited https://www.apple.com/iphone-12-pro/ and was wondering how the "surgical grade & stainless steel" section of the site is implemented. As much as I can tell they are image sequence, the whole animation is not composed of a bunch of exact same size images. Instead, they are only several key frames, and a number of other image sequences that are of a same width and a various height. This particular set of images looks pixelated. Could someone explain to me how those pixelated images are used to create the "light" animation? Are they correlated to those key frame images?