While Jeff makes a compelling argument that this isn't a particularly urgent usability bug, I question the rationale of declining it altogether. It shouldn't be that hard to write an
if statement and a couple of unit tests to fix the problem during some developer down-time...
The reason I think this is a significant problem is because it actively interferes with users trying to do what we encourage/expect them to do. That kind of negative feedback is something that should be decreased whenever possible.
Take this recent question for example. When it was originally posted, I edited in the images because the question was extremely difficult to understand without them. The question wasn't all that fantabulous though, so I didn't bother to upvote it at the same time I made the edit.
Later, I received a comment notification that prompted me to come back and look at the question. It turned out that the user had heeded my suggestion to post their actual code, but they had done so in an answer. I figured they just didn't know better, so I edited the code into the question and flagged their "answer" for deletion.
In the meantime, they added the following explanatory comment into their answer, proving I was wrong to simply assume their ignorance or apathy as to how the system is supposed to work:
(I posted this code as a new answer since I can't add this code to my original post, since it has been edited by a moderator replacing my links by visible pictures, but I don't have the privilege yet to post pictures, therefore I cannot edit my post without deleting the changes of the moderator...)
If that doesn't sound broken to you, I don't know what is. I obviously understand the rationale behind preventing new/low-rep users from posting images, but if they've been censored and approved by another user with full edit privileges, that same user should still be able to incrementally improve their question (but still not add new images), just like we expect them to do.
And, to make matters worse, this is a bug that only affects new and low-rep users, the population most likely to be posting questions in dire need of revising and the least likely to understand how the system works and why they're getting that error.