Meaning
A hand seen from the back with the index finger pointing straight down. It tells readers to look below: at the comments, a link, a form, a thread continuation or the next part of a post.
Creators and shops lean on it heavily: βFull recipe in the first comment πβ It also works in chats to point at a message or photo sent underneath. On platforms where the layout changes, βbelowβ may not mean what you expect, so name the thing you are pointing to. Repeating πππ at length can look like clickbait.