When someone edits my post, the edit summary helps but if I could see a diff view (similar to git) that'd be good. It would allow me to see exactly what was changed between revisions.
You can see what was changed if you click on the edit's timestamp:
That will take you to the revisions page that contains all the changes made to the post:
You can also choose to view "side-by-side markdown" diff, that will show changes not visible in the ordinary diff, e.g. adding blank spaces, changing URL of links etc: