I’d really like to see that, too, but in a generalized version: There should be additional file types that staff users only may upload. This solves your problem (you can say that users may not upload any file type, while staff may upload images), but also the problem that you might want to allow uploading more dangerous file types (say .js) by staff (without an admin doing the enable setting—reload site—upload file—disable setting dance).
「いいね！」 2