There are several small tweaks that I've noticed. There's something about the length of a post, possibly something about the number of comments, and possibly others. There are also penalties for various things. Items without a link are ranked more lowly than those with a link, and some topics du jour have a penalty applied.

All in all, it's actively curated by PG, with small changes to keep the system in balance and running smoothly. Enquiring too closely is discouraged.

It's also plausible that this item will get deleted. After all, this is a site for hackers, not a site about Hacker News.