Overriding CSS background image styles - both images are loaded?

Question

If I have 2 CSS styles that assign background images to an element, and one style overrides the other. Will both images be downloaded by the browser or just the overriding o

Answer 1

It seems in some cases the answer is yes:

http://www.cloudfour.com/css-media-query-for-mobile-is-fools-gold/

http://www.cloudfour.com/examples/mediaqueries/image-test/#t4