What the title says. In Apollo, you were able to configure that if you swipe a comment left, it collapses the entire comment tree from the current top level comment.
That made it easy to jump to the next top level comment after reading responses a few levels deep, if you know what I mean.
Tapping closes only comments further downstream from the comment you tapped though, as it should. Swiping on the other hand should close the entire top level comment tree the swiped comment belongs to.