iPhone DIN: Fold a screen like a sheet of paper … and the content adjusts accordingly. The iPhone Duo is a technical tribute to the DIN paper format. What makes DIN so ingenious is its aspect ratio of 1∶√2, which means that when a page is halved, it splits into two smaller pages with identical proportions, allowing text and images—and now screen content as well—to be scaled without distortion. https://youtu.be/FUfGcZ092b0