Harsh Jpeg compression, courtesy of the Oukitel U22 (Chinese Android phone), one of the first "China phones" with "four cameras", dual front and back cameras, of which only one of the back cameras was integrated into the OS. Never tried the front camera.
The jury is still out on whether this "second back camera" really was a camera, or just a decoy...
It wasn't visible to any test programs I ran on it.
Sold to a friend with absolutely no interest in photography. When, at a later date, I helped him out of a screw-up he committed on his phone, there was still only one photo in his Gallery.
That being the one I shot to show him when I sold it..
Amazingly, this ancient relic is still sold on Amazon.uk:
Shop Oukitel U22-5.5 inch Android 7.0 3G smartphone, Dual front camera (2MP+8MP) Dual rear camera (2MP+13MP), MTK6580A Quad Core 1.3GHz 2GB RAM 16GB ROM Fingerprint - Black. Free delivery and returns on eligible orders.