I just encountered a suggested edit here on Meta that looked like this:
There are two things weird here:
There was no option to distinguish between rendered output and markdown like this:
This is also missing from the review item.
The [off-topic] marked in green in the above screenshot was the only visible change in the rendered diff. This is something an edit should not be able to change. Also, without it, there is nothing left to give the edit the minimum character count (though there may be some invisible aspects that I could not see, because I could not access the markdown view of the suggested edit.