Apple's screen fillet design was patented on 20 12 with the patent number D670286. This patent covers the "rounded rectangle" design of mobile devices, and Apple will use this patent to launch a new round of patent litigation against competitors.
The scope of a design patent is generally determined by the drawings submitted by the applicant. The solid line depicts the patent itself, with the dotted line as the background. In this patent of Apple, there is a lot of background, and only one solid line defines the protected content.