I was talking about this with my friend and I started saying: "i wanna say that there tend to be signs of it being photoshopped most of the time, and there are signs of digital modification at times, that tend to show in the resolution, but i'm not 100% sure. It'd be easier to describe if one has more experience in spotting photoshopped images..."
However he added a few important things that i overlooked:
"Have you ever noticed photoshopped images often lack two important traits of Holga photos?
Softness
And lens imperfection
Two overlooked but very important aspects of Holga images"
Said friend is follow plastic cam fanatic ~
ShadowOfWar