CSS3 background-image with element()

Please hover the div below and watch the background animate.

This is a box that has it's background drawn by an arbitrary element using element().

Below is the image that is used in the above demo for element(). Please hover the image below and watch the background of the element above (a div) rotate.

Please see Firefox 4: Drawing arbitrary elements as backgrounds with -moz-element and 4.4. Using Elements as Images: the ‘element()’ notation.