In this demo:
http://dinbror.dk/blazy/examples/?ref=blog
at paragraph:
1.3: Lazy load image example with low res image placeholder
the blazy plugin uses a lower quality pixely image to preload the image and then serve the high quality image right after.
I don't understand how that is done. Where is the pixely image coming from? how to achieve the same effect with images? lower quality first and then load the right size?