the brightness slider is just made-up nonsense

Is it using screen HDR?

yep

It’s so jarring when I see HDR elements on my dimmed screen

It’s like you put a sticker on your phone

that is insane

i changed my mind this actually looks pretty dope

Is the gimmick of HDR being able to independently control brightness of each pixel or what

on Apple, the way it works is that it just allows colour values to go past 1, 1, 1 in a way where they “naturally” extend past beyond screen brightness, which they call EDR independently controlling brightness of each pixel is just how OLEDs work, but this isn’t necessary for HDR; mini-LED LCDs only have control over the brightness of larger lighting zones but can still achieve very good HDR

gyroscope ?

yeah; the built-in fixed tilt values aren’t very reliable so it’s just a really basic integrator and lowpass on the raw data that slowly approaches 0