I wish it did that too. I was editing an item that has no front box art: http://vgcollect.com/item/13473 It came bundled with the Aladdin Deck Enhancer and has no box art but when I tried to use the cart as the front box image, it was denied every time. I eventually just used the title screen as the front box art as per the database guidelines, but i/'d like it better if there were no front box art (Because there isn't) and the image that showed up in the database was the item/cart.
Even that entry is wrong. It should not have a front or back box art on the entry. It should be like these 2 examples from Game Gear [JP]
Nazo Puyo: Pack-in game only, no box was made.
http://vgcollect.com/item/9046Here is the hardware it came with:
http://vgcollect.com/item/94451Currently, the database does not allow us to attach entries to each other. So we cannot right now make it so Nazo Puyo is a child entry of the Nazo Puyo Game Gear. So we have to deal with artwork issues like this. Where there is no "box front" or "box back" for pack-in games, or some of the other types of entries that the site has expanded to cover.