Almost each game got it's own artstyle (except for some FPS), some are realistic some are not. Take Driveclub and Pcars for example even though they both TRY to look realistic and pretty much succeed in their own way (Pcars a bit to sterile, Driveclub a bit to romantic at times), they are still pretty much distinctive.
So the difference in art style is what makes the game unique and defers it from other comparable games with just looking at a single screenshot. Whether that shot is realistic or sell shaded doesn't make that much of a difference for it's definition of art since one will be more pleasing to the eyes than others which comes down to personal taste and the amount of effort put into it which is mainly influenced by the raw graphical prowess.
The order has the victorian London as decor and a 1950's filmlook and looks very different form uncharted and the last of us, which also looks different. Even though they are all cinematic games.
Please excuse my (probally) poor grammar
