Often when looking at photographs, we assume they are true, that they recorded an actual event in a particular moment in time, captured with the alchemy of light and sealed with a chemical reaction.

But photographs are just as often—and perhaps, more often than not—faked. They are staged, cropped, edited, amplified, quieted, and tied to very specific perspectives. Photographs are rarely, if ever, “true.”

The Vancouver-based photographer Jeff Wall, who investigates precisely this in his work, is dedicated to probing this boundary between reality and fantasy, and seamlessly blending fact and fiction.

In an exclusive interview with Art21 as part of the Extended Play series, Wall explains his 2014 work Changing Room, which shows a woman in the midst of trying on clothes inside what looks to be a department store’s fitting room.

Her bottom half is clad in a floral-patterned skirt, while she pulls a wildly printed frock over her head, obscuring her face. We can see that she’s standing opposite a mirror, flush against the changing room wall.

Production still from the Art21 “Extended Play” film, “Jeff Wall: An Impossible Photograph.” © Art21, Inc. 2017.

“It’s not a mirror image, because if you look at the hangers, they say ‘Barneys’ on them, not backwards,” Wall says in the video. “Therefore, the only thing that you can be seeing is what the mirror sees. So, that’s a picture that can’t be made.”

This slippage between fact and fiction is at the heart of Wall’s work.

“If you pay attention to that picture and enjoy it and look at it—get involved in it—it’ll come to you. And when it comes to you, it’ll be exciting” he says.

So the next time you scroll through Instagram or flip through the pages of a magazine—or take a look at one of Jeff Wall’s photographs—remember his words: “The most beautiful artistry is hidden.”

Watch the video, which originally appeared as part of Art21’s series Extended Play, below. The brand new 10th season of the show is available now at Art21.org. 

This is an installment of “Art on Video,” a collaboration between Artnet News and Art21 that brings you clips of newsmaking artists. A new series of the nonprofit Art21’s flagship series Art in the Twenty-First Century is available now on PBS. Catch all episodes of other series like New York Close Up and Extended Play and learn about the organization’s educational programs at Art21.org.