Surfacing has come in many different forms. The UK version is a normal CD, there is a limited edition Singapore Gold CD, another version comes in a cardboard sleeve around the case, and there was a Canada-only release which came with this bonus disc
The disc is an extension of Surfacing - a couple of rarer tracks and the continuation of the multimedia interview.
As with all Nettwerk multimedia products, it's professionally done and oozes class. Even the bit where Sarah performs to her dog. Don't forget to hunt those easter eggs!
It is available through Nettwerk's merchandise web-site.