Discourse changes to posts

I’m still confused about the orange pencils. Over in “Test-dont read.(sorry folks,I already miss the old site!) - #72 by JackieLikesVariety” I just made a post, and edited it twice, but I don’t see anything that indicates that (to me or anyone else).

In GQ there’s a thread, “Term conspiracy theorists use” which does have the orange pencil. The OP did indicate (with a manual “ETA:”) that the post had been edited–so, does that mean that sometimes the system does show an indication of a user-edit? If so, when does it do that, and when not, and why?

Alternatively, if that orange pencil is for a system-edit, why the heck would Discourse have edited that OP? The only such system-edits I’ve run across so far have been when you quote the entire post for the post right before yours, which presumably wouldn’t apply to an OP.