EDIT: Help received!
For anyone who might be wondering how the heck to navigate Goodreads, and how to solve this problem, here's what I found out.
Even though "delete" shows up as an option for images that have been uploaded, and clicking "delete" tells you that you need a librarian, this is misleading, and is actually not the case. It turns out that Goodreads, as of Oct. 2013, is not set up to do what I needed it to do. You actually have to add yet another edition of the book, and then make sure you notate that it is an alternate cover edition for a specific ISBN.
I need assistance. I had librarian status on Goodreads for my novel for all of two seconds. My cover has changed for both editions of my novel - well, it changed a long time ago, pretty much almost immediately after seeing it lumped amongst the other covers in the catalogue. (Thumbnails can look good all they want, but the real thing we should be testing is how it looks when we put it together with other covers! :) )
But by then, I could no longer change the cover on Goodreads.
I have been hoping a librarian will come by and see that little note I left them, but so far, nothing. I have been hesitant to really use Goodreads, because I want the real cover used. But I don't know how to contact a librarian!
I am asking for any librarians to help. I just need my cover image to reflect my actual cover. All necessary links are in my signature. I can return the favor somehow, perhaps a shout-out for one of your novels on my blog? Just let me know. I would really appreciate the assistance. :)