Why do browsers inefficiently make 2 requests here?

Question

I noticed something odd regarding ajax and image loading. Suppose you have an image on the page, and ajax requests the same image - one would guess that ajax requests would hit

Answer 1

Your fiddle tries to load a resource from another domain via ajax:

I think I created a better example. Here is the code:

You can test the page here.

According to Firebug and the chrome network panel the image is returned with the status code 200 and the image for the ajax request is coming from the cache:

Firefox:

Chrome:

So I cannot find any unexpected behavior.