Either way, it’s genius. I don’t know why that isn’t offered in more vehicles.
That is exactly the purpose and required (or via dashboard electronics) in most vehicles in the EU after a certain date (don't know which exactly and also I do not know the exact rules but every car i've ever owned had those). Automatic is also fine. They are not meant for "Alternative High beam" as what some people use them for.
The "clip" on the rear view mirror is also not meant for looking at your kids in the rear. It's meant to flip the mirror up so the reflection is not by the mirror but by the refractive index of the glass any you see a "dimmed" image of the high beams behind you.
Usually it is supposed to be calibrated so that the highest position is the default no load in the back position, but you can recalibrate so that it is in the middle if you want.
I wouldn't call them shopping carts either but if you come from the US you might have different size expectations.
I don't have a level spot with the recommended distance so we went with some tape on the garage door as a reference. We got them a tad low the first time and raised them up a bit. I can still see and apparently everyone else can too because nobody is flashing their lights at us.
Our other vehicle is a 2014 3/4 ton Ram pickup. Nobody ever flashes me in it.