Seems more like a simple counter that increases the build number and goes through some (hex?) letter combinations along with it to find a build that might result in something different. It would really only perhaps show something if a build is in fact on a server and the server is configured differently to respond to non-existing files vs. to unavailable/hidden (for lack of a better word) files.
And yet here we are discussing it in a thread that you started (when even tons of those who actually care about the beta in one way or another often don't even post in beta threads, let alone start them).