Comment 6 for bug 1531913

> If it's the image to be shown when there is an error loading the image, then the API is wrong,
No, it is exactly that. That is the reason why fallback was introduced for, in case the art image fails to load (server is overloaded, resource is gone, etc) and then we show a fallback.

It is documented like that as you can see in https://developer.ubuntu.com/api/scopes/cpp/sdk-15.04.1/md__r_e_l_e_a_s_e__n_o_t_e_s/ "This allows a scope to specify a category-specific fallback image in case the artwork for a result cannot be retrieved."

You can argue that a blank URI can not be retrieved and thus the fallback needs to be loaded. My argument is that a blank URI says "no retrieval needed", so it is not an error and no fallback is needed.

I'll implement what you're asking for and let others decide if it needs to be merged or not.