Theme Viewer: How to duplicate?

I’d like to duplicate the look and style seen in the WordPress Theme Viewer and was wondering if anyone can suggest what plugins I would need. Was this even done with a WP plugin or was it custom made?

I want to display a bunch of thumbnail images that are screen grabs of websites that people could go to upon clicking on the images (this is for a website review site). The ability to sort (as seen in the sidebar of Theme Viewer) would be nice also. Thanks!