Sometimes a question pops up on the main page with the last touch being done by the Community♦ user (e.g.
2h ago Community♦ 1). But if you click on the question itself you don't see any modification by Community♦ at all. I vaguely remember that this can happen when questions are poked to float to the top of the main page --- for example when some algorithm decides a question hasn't received enough attention.
It would be nice if all actions by Community♦ were visible on the respective "/revisions" page of a question. Note that some actions (e.g. tweets) are visible even though they don't actually edit or revise the question.