This is the third part series of what we think phones would look like in the future. The next big thing in display technology in the near future seems to be flexible displays. There are a few foldable phones like the Royole FlexPai, Samsung Galaxy Fold, and Huawei Mate X.
Instead of unfolding a phone for more screen like with the FlexPai, you could stretch it out to increase its size, sort of like a rubber band. All you have to do is pull the phone from two of its corners diagonally.
This type of design would let you quickly increase the size of the device when watching videos and make it smaller to fit in your pocket. For it to work, the vast majority of components would have to be stretchable, not just the display.
Obviously, there would be a limit to how far you can stretch a device. If that limit was 50 percent of the size of a phone, for example, it would mean you could transform a 6-inch display into a 9-inch one.