The demo is pretty unfair. If you want to package lots of the same image, you just use it and let cache control do its job. If you want to package lots of diffe

The demo is pretty unfair. If you want to package lots of the same image, you just use it and let cache control do its job. If you want to package lots of different images, you should use a big sprite (again, server-side packaging without any js). If you want to make image loading look slow, do what they did in the demo.