The "super copyright" comment has less to do with their ownership of the copyright, and more to do with the rest of the context about the owners not being able to exert copyright claims due to fair use. (This of course is predicated on the assertion that the usage does fall under fair use.) The "super copyright" comment is alluding to Zillow attempting to assert something that even the original owners cannot (i.e. a "superset" of copyright rights).