eBay had made available and then taken away, the new feature that gives sellers the ability to add eBay hosted photos even after a bid is placed.  Fees apply so, please read the fine-print carefully!  Here is the original announcement:
 
Sellers can now use the Revise Your Item process to add eBay-hosted pictures to their listings, even after a bid has been placed for that item or if fewer than 12 hours remain in the listing, similar to how you can add extra description. In addition, if you didn’t list your item with any pictures originally, you can also select any listing upgrades (such as Supersize) that you want to include.

Please note that as before, any pictures already included when a bid is placed or when fewer than 12 hours remain in the listing cannot be edited or removed. You will also be unable to add pictures if both a bid has been placed and fewer than 12 hours remain in the listing. For more information about revisions for active listings, please go to the Revising Your Listing Help page