@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

menuitem#AddonsMirror {
     -moz-binding: url(chrome://global/content/bindings/menu.xml#menuitem-iconic) !important;
}

menuitem#AddonsMirror { 
     -moz-image-region: rect(176px 224px 192px 208px) !important; list-style-image: url("chrome://cutemenus/content/res/mosaic.png") !important; 
}