As exhibition design goes, “Illuminated Archive”—-a meditation on the history of exhibitions at the Phillips Collection—-soars to new levels of eccentricity. Not only does it consist of just a handful of works by the Yugoslav-born artist Vesna Pavlović, but it’s been mounted in a stairwell. That’s right, a stairwell.

The exhibit, based on documentary materials from the Phillips’ archives, includes three manipulated photographic works that “explore the idea of transparency, both photographic and historic.” Each is mounted on a different floor as visitors descend the staircase. (Not while nude, one hopes, regardless of the “transparency” theme.)

The images succeed to varying degrees. The one featuring a ghostly, photographic-negative rendering of an exhibition of Albert Giacometti sculptures from 1962 is the least manipulated, but also the most dull.

More stimulating is a piece based on the 1962 exhibition of works by abstract expressionist Mark Tobey. The screenprint on Plexiglas shows a gently curved room, rendered hazily in benday dots—-a wise choice for visual interest, though an odd one given that Tobey’s work tends to be more organic and less mechanical than the Pop artists who made the technique famous.

The final wall-mounted piece (above), based on a 1957 “Swiss peasant art” exhibition, is the most inventive. Over the indistinct image of the exhibit, Pavlović has layered a cracked, translucent surface that mimics gel containing tiny air bubbles.

At this point in my visit, seeing no sign of a “35-foot transparent curtain of digitally manipulated images,” I thought the exhibit wasn’t fully hung yet, and I left. I was wrong. As it turned out, the promised curtain was so subtle as to be almost invisible.

It hangs, in two parts, in the tall window that allows light into the stairwell. At first – and second – glance, it seems like an ordinary, functional window covering. Only upon closer inspection (or, perhaps, when one stumbles upon the inconspicuously placed wall card) does the curtain reveal a delicate pattern of light and shadow.

To its credit, the curtain’s printed patterns tend to clash with the actual patterns of light and shadow coming through the window, forcing careful viewers to decipher a playful visual riddle. Still, the ease with which the work can be overlooked suggests it’s closer to decoration than art. Unless it’s simply a 35-foot-tall postmodernist joke.

Through Sept. 28 at the Phillips Collection, 1600 21st St. NW. Tuesdays, Wednesdays, Fridays, and Saturdays 10 a.m. to 5 p.m., Thursdays 10 a.m. to 8:30 p.m., and Sundays 11 a.m. to 6 p.m.