In “Her Story” you watch a handful of video clips of a staged interrogation. You then have the option to type in searches for key words—if you type the right words, you get more clips from the interrogation. If you do enough of the right searches and watch enough of the right clips, you find out about the murder.

Though it is innovative, award-winning and thought-provoking, “Her Story” isn’t art. Or, while it is art in the sense that creative products by creative people are, broadly, art, it isn’t art in the sense of the sorts of things usually covered in Artillery or Artforum or that generally appears in museums—it’s marketed as an avant-garde video game. You may have guessed this from the description for one major reason: it sounds like it takes too long.

Our attitude toward what constitutes the lines between “video art” and “a movie” and “interactive video installation” and “video game” reveals something about the nature of the definition of fine art in the last 100 years: Art is short things. If an adult with their clothes on is happily interacting with an inanimate object for over a half-hour and not producing anything from the experience there’s a 99% chance that object is marketed as a game.

The one-minute Six Men Getting Sick (Six Times) is art, Eraserhead (no less baffling, and by the same author) is a movie. It has currency with a wider, if still niche, audience far beyond people who go to museums. The few long film/video pieces unambiguously commercially classified as fine art—such as Matthew Barney’s films—seem to have landed there by dint of both a long pre-long-form gallery pedigree and by making a point of prodding the audience to see how long its attention can be held/sustained despite the absence of narrative. The “Cremasters” are essentially about testing the boundary of the audience’s patience for anti-narrative in the same way older artists might’ve tested the boundary of the canvas by attaching a broom or a receipt to a flat painting.

But the reason why these commercial and mental categories—narrative films with strong plot arcs that appear in theaters before wide audiences vs. moving talking-art objects in museums that don’t have plots, open-ended video installations in galleries vs. video games in peoples’ houses—even discretely exist is interesting.

The art-loving classes have no philosophical opposition to The Long Experience—they respect the full Artness of Burroughs novels and Werner Herzog films, but there is a boundary unease about what gets in to the places we show and talk about fine art. The actual reason is historical: Once art was largely in wealthy homes, then: democratizing eras and public museums. This is an old story—the easel-sized sitting-room painting was replaced by the portable murals of the Abstract Expressionist era.

But something else happened as well: art went from something you (lucky few) saw every day on your way to open the curtains to something you (now any motivated citizen) visited between something and lunch or between lunch and something. Just as this democratization brought on a change in the size of art and in the content of art, it also brought on a change in the way art expected itself to be taken in.

A powerful and hidden force in defining what “art” means since 1900 has been the fact that the most commercially successful fine artists have adapted their work to reward shorter and shorter viewing times. Whatever the experience of art used to be, the Platonic ideal for the postmodern work became: you go, you look briefly (at Stella, Warhol, Hirst, Walker,) you have your mind blown, then walk away. The curve of fine art has been bending toward the haiku—and not because the haiku is inherently deeper or more relevant to our new century than the epic (or even to the 200-page haiku anthology), but merely because of the way we have to interact with the physical spaces we keep fine art in.

But there has always been a counterforce: ordinary people curate their homes and every creative industry outside the fine art business has been happy to oblige. Video games advertise themselves on not just their length in hours but their replay value; comics and even the hippest graphic novels offer image after image strung together by narratives that keep their viewers reading a single artist years longer than they’ll read an art history text full of pictures they enjoy just as much or more.

Short-form rewards certain qualities: simple shapes rather than complex ones, the one-liner over the long game, the topical rather than the philosophical, broad-brush messages over analytical ones, juxtaposition instead of immersion, the identifiable over the abstract, big instead of small. Noble work has been done with these tools—also most advertising. But let’s not fool ourselves that they show up in our galleries more often than in the outside world because they’re better—they show up in our galleries because they’re galleries.