How can I get artwork for my "Collections" ???

[seamus]

I'm trying to set up the "Collections" feature to help with organization. I stumbled through the interface with some help from documentation and (mostly) forum posts here and on redditt. I selected an option to have Jellyfin "automatically" id and create "Collections" for me. With a few exceptions, that seems to have gone OK except for one thing: ARTWORK/IMAGES 

I now have 44 "Collections" in my movie database. Only one of them has any artwork for it: The "Lethal Weapon Collection". And though I've waded through the documentation on this feature, I've been unable to find any guidance on HOW to obtain images for a collection. 

The only thing I can even see to TRY is clicking the "triple dot" widget in the LRHC of the "Collection". Just as with "Movies", it provides a dialog which includes "Edit images", but there do not appear to be any images available when I search by clicking the "magnifying glass" icon. 

I should probably add this: Most of the "Collections" that Jellyfin has created for me are not actually box sets of CDs/BDs - they are simply individual CDs that I've added piecemeal over time. Here's a sample of what I see: 

   

Thanks,
~S