Audemars Piguet

...it must be worth:

What makes it age like that? That is super unusual, especially if the case is air tight?

I do not have an answer

Everything has a lifespan. Scientifically, it can be said every set of molecules can have a "half life." The degradation of the atoms or molecules can be measured. Now those measurements tend to be in thousands of years sometimes. But things like watches, where a dial is painted or treated, there can be a lifespan to that treatment. Watches also undergo warm and cool temperatures, light and dark, UV and no UV, and varying air pressures. These can all affect the color treatment on a dial. Just like it can affect the paint on a car.

It's not magic, it's just the normal aging of materials.
Dials are usually made out of steel and what's called "patina" is basically rust

For the explanation. I had not seen that before.

I feel guilty of being so lazy having photos by phone instead of my beloved camera. haha