@shaddack - it is from a digital forensic tool designed to detect photo manipulation. It measures a number of digital criteria from level of noise, to color space, to level of jpeg compression artifacts, to feathered edge detection, to cloned area detection. Photoshop can match things very closely visually for humans but leaves its digital fingerprints all over the image especially when the techniques used are designed to look smooth and flawless. Even the best photoshopper is only able to make alterations that are not visibly detectable by humans, computers are much better at detecting these digital alterations.
A number of companies make these tools, many of them are actually photoshop plugins! 
For example, lets say I add a pigeon to the image like so:
(just a quick job, so no judgey…lol)
The tools see it sticking out like a sore thumb…
