The effect is implemented with a background-image shifting (plugin bgpos.js) 
Base plug-in - a picture which is displaced with the help of JavaScript (jQuery) and there is an unusual effect, reminiscent of Flash. The shift can occur not only vertically or horizontally, but at the same time on two axes, and at different speeds and in different order. The menu uses the Background-position jQuery plugin.
Images used in this example:
Related plugins
