Although this is marked as solved, I’d like to suggest an alternative approach. I always like to create a workflow that could be maintained by a novice user even if it means a bit of extra programming.
So why not create a CPT called Brands which contains just the title and image? I’d position its admin menu low down to avoid visual clutter or even make it a sub-menu, then create an ACF field as a relational post-object that would be selectable by title but displayable as an image without having to mess around with FTP uploads and careful file naming.
