I wonder how much of this depended on the differences in device screens. In 2015 there was a lot more variability in display technology, lower resolutions in general and worse color fidelity. OLED was uncommon and expensive, you probably only had an IPS display if you worked in graphic arts, and a lot of people were still using standard LCD monitors backlit with fluorescent tubes, which meant that the black depth was limited and the detail in dark regions of an image was frequently not visible on the screen.

In the drawing, the surrounding background and the hard black lines on the lighter version are probably causing that we don't compensate the light in the same way in both drawings. We are not given the same picture like it happened with the original photo.

Brains are weird.

Yes and they are extremely flawed too.
The only reason we think we are smart, is that every other life-form we know of is even stupider.

It's funny; I have a pretty extreme night light filter (i.e. blue is almost completely removed) and even through that it at best looks.. maybe gray and black?
Then when i turn the filter off it just becomes hilariously obviously blue. Like.. It's blue: you can tell by the way blue light is hitting the retina 🤯. At most i could stretch myself to consider it purple-ish, but that's just blue with some red mixed in..

But yeah i can theoretically understand thinking the black is golden, though even then it's just not quite right for me to ever see it. Like if the light was significantly exaggerated THEN i could probably force my brain into considering the black parts to genuinely be at least dark gold material.