Brilliant post but I'll admit to being confused by one thing. In the EXIF it says there is a focal length of 2.5mm, but you then recalculate it to 0.3mm. Why take the angle as wrote but not the focal length? It doesn't change the math much, 110mm instead of 13mm, but I doubt the Nokia is capable of macro focus at 13mm. 110mm seems a reasonable bottom end of focus for a potato phone.
The sensor is tiny and the there's some degree of zooming involved.
Combined with severe downscaling, any out of focus weirdness would appear to be acceptable.
This led me to believe that the lens itself was a something-2.5mm and some degree of zooming was allowed, the Exif simply didn't record it.
Then there's hyperfocal distance which was 0.12m, this means everything 0.12m away is in acceptable focus, which means the focal point is about 6cm away. That's also a reasonable number to be photographing a monitor. The numbers based on using 2.5mm appears to produce something close.
That's when I tried to replicate whatever MAN-d made with my own phone at around 160 FoV and I was able to do it, so I just went with whatever I've calculated.
Chances are, this cheap piece of shit phone doesn't record the camera Exif adequately. Unless someone gets a hold of one and tries it, we're left with a working distance of around 1cm, around 6, or around 11.
Either way, that's a monitor photo. "She" didn't crop anything, so there's zero chances she was holding the phone in reverse.
The Exif also records circle of confusion (coc), I can use that to calculate the working distance differently but that'll involved calculus which I am not in a mood to do right now.