VeloViewer of Mystery

I've stumbled onto VeloViewer.com. I don't know exactly what it is, but is seems cool. I created the image above from my Strava data and apparently it keeps it up to date (edit: Actually, I don't think it does.) There's all sorts of ways it can display my Strava data, and I even almost understand some of them, but not this one. But I still like it, because it's geeky cycling stuff.