If you read magazine articles on the 'how to create fine art' it would appear that anything with minimalist composition, high contrast B&W and square cropped is 'fine art'. Or those using a 10-stop ND.
Or to put it like a local gallery, similar images to my first sentence with a much higher than normal price tag
Seriously though, I think 'fine art' means so many things to so many different people that it's difficult to pigeon hole it - perhaps 'fine art' = 'Wow factor' ??