The original Game Boy and the Game Boy Pocket had very poor pixel response times, resulting in heavy ghosting, perhaps not much different from the ghosting achieved in the video. Later, LCDs fixed the ghosting, but LCDs never achieved the reflectivity of electrophoresis-based e-paper screens. Reflective LCDs are always more grey than white.

LCDs are inherently transmissive rather than reflective (like the electrophoresis-based screens from E Ink) or emissive (like CRTs or OLED screens). To make them reflective, the ambient light has to go through the liquid crystals and a polarization filter twice, since it is only reflected by a mirror surface behind the screen.

Unfortunately they are not strongly transmissive, so they absorb a lot of light, especially when it has to pass through twice. This is not a problem for LCDs with emissive LED backlights, because the light has to pass through only once, and LEDs are highly power efficient anyway, so you can just make them brighter. But you can't simply dial up the ambient light on reflective screens.