At some point, at least at the time of this report, we had functional diff displays when you expanded a
revision event on the
activity tab of a user's profile.
Now, however, it looks like the following mess of algae:
The only change in the above is that the word "take" there was originally "tak". An
e. That's it. Good luck finding it.
It seems that the diff display has broken in some fashion so that it is under the impression that all of the post is new. I've seen this on all the Beta sites, here on Meta Stack Overflow, and a smattering of graduated sites, so I'm inclined to believe it's a global issue.
Could it be fixed to show the actual differences in the revisions?