Hi jakeheller.  I think the subfolders or subdirectories can be  Image Category, 3D model Category.

Image Category - Architecture, Organic, Abstract, Characters, Fantasy, Game Art, Vehicles, Still Life

3D model Category - Architecture, Organic, Abstract, Characters, Fantasy, Game Art, Vehicles, Still Life

This way we only have to navigate to the subfolders we need to add content to. Maybe even adding custom folders will be an option. This idea is similar to Cafepress account management.

I like the text or thumbnail option as well. Might speed up the refresh of the page in my accounts.