In my case, an artistic film is a successful attempt to innovate and improved on from its great predecessors.
In writing, editing, cinematography, shot compositions, production design, art direction, costumes, sound, music….all of these aspects combining on screen to show the audience something that comes across as a novel cinematic experience.
Certain films which pay homage to a great predecessor but falls short or films that claim to be original yet feels derivative and mediocre can be looked at as pretentious.
About Nightcrawler, I can recall that the main character was hard driven in a smarmy sort of way. I think I remember I didn’t like watching this character but he was ably portrayed by Gylenhall? As a piece of film per se I thought the filmmakers knew what film they wanted to do and they did well technically in achieving it.
Shape of Water. What a disappointment. It was painfully underwhelming. A dud. And yet it won Best Pic at the Oscars. It was an artistic attempt by a truly talented filmmaker Del Toro but it takes more than great lighting, special effects, music etc. to create a masterpiece.