Chinese smartphone producer TCL unveiled an interesting new smartphone prototype (concept?) called the Fold ‘n’ Roll.
As you can see in the video, the device has a 6.87-inch OLED display when fully folded. It can open up (out-folding) into a 8.85-inch display, and then it can open even further to a 10-inch tablet-like device using a rolling mechanism. The display itself is produced by TCL's CSoT subsidiary.
This is an interesting design concept - TCL has already been showing foldable and rollable OLED designs and the company promises it will launch its first device with a flexible (foldable?) display by the end of 2021. It also promises to show new designs in the future, as the company experiments with new display technologies.