We already mentioned that the next iPhone will not have a curved screen, or at least not curved like the Samsung Galaxy S7 Edge, however, according to Nikkei, there will be a slight curvature to the sides.
The iPhone 8 will have a slight curvature in the glass which will allow it to adhere better to the screen. Apple does not implement particular functions in curved, which will play only an aesthetic and design role.
This news comes just after that of IHS Markit, where it was argued that the next iPhone would have an OLED flat panel, with a 2.5D curved glass at the ends, like the current iPhone 7:07 Plus.
Ming-Chi Kuo instead, just as Nikkei, had added that in addition to 2.5D glass, also the OLED panel may follow the slight curve of the glass, to obtain a much more refined design.
This last hypothesis seems to be the most reliable to date. Considering completely virtual bottom area with Home key and dynamic function keys that appear depending on the applications that we use, the concept that you see in the picture above might actually look like the next iPhone.