Bandwidth-wise, images are hogs. They are the largest average web site payload (62%), and they are most often the content bottleneck. When images arrive, they come tripping onto the page, pushing other elements around and triggering a clumsy repaint. They come “chop chop chop chop chop down” or you get nothing until suddenly “boom!” out of nowhere there it is. We all know what I’m talking about when I say “chop chop down” and “boom” and it makes us a little bit sick, because we sense how much time we’ve lost of our precious, short lives, waiting for pictures to download.