[madrobby]

Media resolution is relative, as people zoom in on mobile phones all the time.

For stuff like photos, just supply a larger resolution JPEG that has lower quality. This will look great when smaller and when zoomed in, while keeping the file size in a range that is ok for mobile.

[michaelbuckbee]

This is an interesting approach I hadn't heard or tried previously. Do you have any guidelines as to image quality and resizing?