Picture and thumbnails on same page - how to add a "loading gif"

I use this "addon" to maxigallery: http://wiki.modxcms.com/index.php/MaxiGallery#Picture_and_thumbnails_on_same_page

However, when I click on a thumb it takes some seconds until the big picture gets loaded. I would like to display a nice little gif that indicates there is a loading process going on. (like the gifs you can create on ajaxload.info)

Any help is appreciated

Regards,

Konsum

here’s a how-to: http://bit.ly/cq88Kn