Earlier quoted context omitted.
In principle it's possible to measure the ambient light and set the emitted light to simulate reflected light from paper so that an OLED looks indistinguishable from paper. Next gen QLED displays might have the brightness to pull this off even in bright sunlight.
If you really want to simulate reflected light you also have to be able to control the angle of the light that you emit, and you want to absorb incoming light almost completely otherwise there'll be a conflict (glare, in particular). I suspect that it might be easier to improve reflective displays, but I have no expertise in this field so maybe I'm completely wrong about that.
Uniform emission is fine because paper has close to Lambertian reflectance. "The apparent brightness of a Lambertian surface to an observer is the same regardless of the observer's angle of view." [0]
> and you want to absorb incoming light almost completely otherwise there'll be a conflict (glare, in particular).
Or make sure that the display itself has close to Lambertian reflectance and take into account its color in the emission calculations.