This is the Flickr version of the XXL2-r theme. It pulls all images from Flickr. The manual explains how to do that.
It has the same options and look as the XXL2-r theme, but no play/pause button.
The delayed fade-in effect is made with the Hide 'n' Show stack*. Tutorial is in the manual of this theme. Refresh the browser to see the effect again.
*You need the Stacks plugin for this. Stacks are not included in this theme.