I could be wrong, but it seems he just mounted '/porn' directly as '/' ? Efficient, I guess.
..actually, there seem to room for more improvements; I'm not sure there's any need for an 'operating system' on the system - a small fap-app (tm) could likely handle all content on the system ? Work documents could be injected in to the fap-stream (c) when he needs to stop ? That would release many gb for even more fap-ability (c) ?