The increase of the screen surface is soo 2014, and the reduction of bezels is so 2019. A new trend in smartphone design is in the foldable screens, but it could easily be in the addition of an extra display. This idea is not so young. Yota tried it with the addition of an ink display at the back, and LG was experimenting with the Dual-screen accessory.
LG’s idea is not so bad, but the Nokia Archive also did a nice concept of a Nokia smartphone with two screens installed.
Nokia Archive’s concept was most likely inspired by Nokia N900 or Nokia C6-00 that could extend a QWERTY keyboard to speed up the typing. Nokia N97 and Nokia N950 share a different mechanism to access the keyboard, but the idea is the same. This concept phone would have a second screen instead of a physical QWERTY keyboard that would be used as a keyboard or for some other purposes. Also, that part would carry a front-facing camera(s) and could be partially extended to take a selfie. I believe that this second screen could be used as a quick launcher for some apps or could house some widgets when the phone is placed horizontally.
I would place cameras horizontally to get more usable space and would remove the Nokia logo at the bottom, or put it horizontally to match the camera position.
Since the main screens are thin, the phone wouldn’t be so thick, but if it would be, I think nobody would mind since it is bringing two screens to the game. The only question is how much would the screen move, completely or partially and would the partially extended second screen hurt the ergonomy of the device when held vertically.
Anyway, a nice concept and the same approach could be done to Nokia N95 :).