To modify the fields you see next to the image in Specify 7, you need to modify the Attachment form definition in the form definition XML. It looks like you have already customized this in your database!
Thanks for the reply and for adding the feature request.
I did try to modify the ObjectAttachment and CollectionObjectAttachment view definitions, which I copied from global.views into my fish.views, but I did not like much the result. I will try your suggestion of a form table in a button dialog.