My best guess from the way it looks is that Active is like a forum or imageboard sort, where new comments "bump" old threads to the top. Hot appears to be more like "rising", new posts that are interacted with more than others. Both probably make more sense with greater volume, but neither seem perfect for the structure of the site. I would also think "tuning the algorithms" is probably in the "when we get around to it" bucket for most of the people who would be handling that.

I wish people used the term HMD (head mounted display) for stuff like this. It's not VR, there is no motion tracker or interaction with a "reality" that is "virtual". It's just really small screens really close to your eyes.