RANDOM question.

I noticed some posts have little pages on them with #'s of the last few pages of posts. So if a post is up to 32 pages next to the post it has a little white paper square with 31, and one with 32, that you can click to jump to those most recent pages.

At first I thought it was just posts over a certain # of pages, but my monthly due date post is at a HIGH # and doesn't have it. And I saw one post with it at just TWO pages!!! How do they appear? How do you get them to? I would LOVE to have them on my due date month club post!!!!