I recently noticed that on a USB stick that I used with my Prime 4, I have a folder ‘screenshots’. I was surprised to find what actually looks like a screenshot of the Prime 4 display. I have no idea how it came there. Tried to reproduce it by connecting a keyboard and pressing printscreen, alt+printscreen etc, but that didn’t work. The image looks too perfect to be taken with a camera. It definitely looks like it has been done internally.
Here it is: