The one of the left ("Moonlit Dreams") is just obviously fake-looking, to me, even before the article's tells. The clouds-behind-the-moon issue is pretty obvious, which might be twigging my "blatantly fake / videogame capture" detector.
To everyone saying "it's Art, they can do whatever they want" ... I think that's true, but if that's your approach, then you need to make Art that looks better than something I'd airbrush on the side of a van. So the demands are a good bit higher once you're no longer claiming the implied authenticity of an actual photograph.
It's like saying something's a True Story when it's not. When it's not, then you're held to a much higher standard of quality and creativity. Saying something is a True Story when it's not means you want to write fiction, but have the gentler criticism that is applied to true stories.
Same with photographs.
As Photoshopped images, those photos are freakin' cheeseball.
To everyone saying "it's Art, they can do whatever they want" ... I think that's true, but if that's your approach, then you need to make Art that looks better than something I'd airbrush on the side of a van. So the demands are a good bit higher once you're no longer claiming the implied authenticity of an actual photograph.