I agree that this is a problem. I’ve spent far too much time trying to find solutions for images in responsive designs and none that I reviewed work. (research at http://cloudfour.com/responsive-imgs-part-2).
But I find the arguments that Henri Sivonen made against putting the information in the header to be compelling: http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2012-February/034642.html FWIW, there was an RFC back in 1996 describing a similar request: http://tools.ietf.org/html/draft-mutz-http-attributes-01 Personally, I’d rather see a new element or a new image format a la the "add html-attribute for 'responsive images'" thread going on right now. Or if it is headers, I’d like to see something that is more inclusive and could be used for servers requesting different information instead of codifying something only for screen size. -Jason
