Said the Kunsten Museum's exhibition guide, about the 2 completely blank canvases it chose to display, quoted in "A Danish artist has been ordered to repay a museum after delivering blank canvases" (NPR).
The museum had advanced Jens Haaning over $75,000 so that he could recreate an earlier work of his in which he attached actual cash to the canvas. In that earlier work, the money was supposed to represent the wage gap between Danish workers and Austrian workers. Haaning is considered a "conceptual artist," and the new work expresses a concept that the museum made a show of understanding (or pretending to understand).