According to Feld & Volk, they have been working with the very same factories that actually churn out spare parts for Apple devices for over a dozen years now, and the rather numerous screw holes that you see in the image gallery? Those apparently hail from the manufacturing process, and will not be there in the final production when the rear shell is properly done.
Feld & Volk also figures that the Apple logo is not there just for aesthetic purposes as well, since it could very well hold a Near Field Communications (NFC) antenna. The antenna breaks in the alleged rear shell were also mentioned to be made out of a “non-conductive polymer” that will help insulate the various antennas stuffed within from one another.