User blog comment:DQueenie13/Infobox Idea/@comment-4616791-20120623011103/@comment-24038268-20120624132904

The problem is, we don't have the necessary JavaScript that is used to allow the images to switch. The only way to get the JS is for ExcelCode to approve and add the JavaScript onto the MediaWiki.

As for the Magi Wiki, you don't seem to use that JavaScript (it's not in your Wikia.css, at least), so I'm not quite sure how you pulled it off, but it doesn't work here. Perhaps the default Wikia.css is different from Wiki-to-Wiki?