Screen idea

[Scientific_potato]

I was thinking while i was playing my gameboy about screens without a backlight, and realized something.
it might be possible to use an switchable glass panel (more about it here: https://www.cantifix.co.uk/blog/what-is-switchable-glass-and-how-does-it-work/#:~:text=In the most simple terms,it's very much a reality.) paired with a mirror behind it. in front of this would be a clear backlight & lcd panel.

I honestly dont care if people take my idea, as long as they give credit. i just think it should exist... but maybe the reason it doesnt exist yet is because its stupid? idk, any ideas that might improve this or make this possible/exist just let me know.
oh also, maybe there should be an ideas forum? Edit: it looks like there might be one- though i dont know if its an idea for a forum or an idea forum. (i also just realized that it could be used as a way to take someones idea and profit off of it. maybe not a great idea? maybe a disclaimer saying "BEWARE, ideas may be stolen. dont post anything here you dont want to be stolen")

Edited May 15 by Scientific_potato
Correction

[LordFayreWCairns]

Very much agreed.

[MigL]

A liquid crystal display essentially orients 'liquid' crystals so that they act like shutters on a window.
They need some sort of illumination behind the 'shutter' so you can see an image.
The old color LCD displays worked similarly, and as a result, could never produce deep black color, as the 'shutters' don't seal very well.The problem was solved when they developed blue LEDs so that an RGB display would have 3 thin-film transistors at each pixel that emit their own light and have no need for a separate backlight.

I remember depositing thin films of various types, under vacuum, onto glass substrates, in 3rd year Uni, then applying a voltage across the film and causing it to go opaque, but I don't quite understand what you would do with it?
could you elaborate further ?