That '15 new comments' thing? (Which somehow turnes into 10 after opening.) The one on the main page where I never go anyway? But it's only recent ones, and apparently works only for one's own journal, and not for wherever you commented. If I get it well, on Pillowfort they didn't make it a feature of the site itself (yet?), but a part of user culture - you just post a post and say "hey, you may be interested in those discussions I had recently, wanna jump in?".