The illustration and text alongside make it pretty clear that the displays are different in nature and would serve different purposes
Apple, the largest technology firm in the world by market cap, has received a patent for a device which would use the second display as a dynamic keyboard. The patent titled "dual display equipment with enhanced visibility and suppressed reflections" was awarded by the United States Patent and Trademark Office.
There are two implementations of the design which are described in the patent application. The implementation utilises a permanent hinge around which both displays can rotate similar to a laptop. The second implication allows the screens to be detached and be used separately along the lines of Microsoft Surface.
The illustration and text alongside make it pretty clear that the displays are different in nature and would serve different purposes. One is an LCD and the other is OLED, and hence cannot be used as a dual screen within the scope of the system.
A number of polarised and wave layers will be used on both the displays to make sure that the glare from one screen to the another is minimum. The patent details how these polariser and wave layers would work.
The scope of the device could be futuristic. The dual display setup could provide context-sensitive controls or be used as a sketching surface using maybe an Apple Pencil. However, these experiences would come at a price. Users who choose to transition could miss the traditional feel of using a keyboard.
Though merely obtaining a patent does not mean that the product will definitely come to the market. There are numerous patents obtained by Apple which have never been materialised.