D’oh, just realized that the top few in that list are, indeed, ordered by likes on the parent post.
Even if that’s an interesting metric, it was completely counter to my expectations, I guess as I’m used to systems like Reddit that also weigh the level of activity in the thread. (Number of replies, number of likes in the replies, recentness of the replies.)
Should there be another sorting mechanism (maybe Hotness?) to find those threads?
(Sorry, I’m sure many people have been over this discussion many times.)