I've noticed a graph I'd posted in an Answer (an uploaded .png) has a typo in the legend (had "ploy" for "poly" in one entry, should it get fixed before you read this).
Forseeing that this particular Answer would involve a bit of trial and error, I had made it Community Wiki from the outset. However the prospect of fixing the image got me wondering if one could overwrite the underlying imgur link and thereby fix the "typo" without editing the Answer per se.
No doubt having some revision history is good to refer to, but I worry a little about the storage wasted by the discarded image.