As you can see, there is a link to improve the question. There are also links to improve all the other answers.
is was the link to edit this answer?
OK, animuson figured it out; an edit was pending. (The easiest way to replicate this behavior is to have access to a review queue and open up the answer in incognito mode.)
Since nobody has posted an answer, I'm changing this to a feature-request.
Once upon a time, the edit button would disappear for users under 2k when edits were pending. This was changed so that the button was grey:
The hover text clarifies:
Another edit is awaiting approval for this post. Further edits cannot be submitted until the pending edit is reviewed.
The old behavior is similar to what happens to answers viewed by anonymous users, but not questions.
Curiously enough, "improve this question" becomes "edit" when a question edit is pending, instead of disappearing (I took this pic in incognito, of course):
Clicking on edit lets me edit the other user's suggested edit, although I'm not sure the mechanics at play exactly (is this a bug?).
Anonymous users should either be told why they can't edit an answer, or the behavior should match that of questions.