You're spot on that's the cleanest conceptual way to do it in jQuery. In more recent versions of jQuery, though, $.live is technically deprecated (1.7+). The equivalent new syntax is:
$(document).on('mouseover', 'img', function() {});
$(document).on('mouseover', 'img', function() {});
You want to trigger the mouseover event, not bind to it. And you want to trigger it after the image has been inserted. Unfortunately there's no jquery event for dom insertions. But on firefox you can use a MutationObserver:
MutationObserver(function(event) {
$(event[0].addedNodes[0]).mouseover();
}).observe($('body')[0], {childList: true});