At first glance, they might be identical. Two orange lozenges leaning out of shards of blue. Two paintings purportedly by the same artist. But look a little closer, and you’ll start to notice differences. The one on the left seems clunkier, its gradations in colour less subtle. The palette seems reduced, the brushwork less varied and interesting. The one on the right is Painterly Architectonic (1917) by Liubov Popova, a cubist and suprematist painter who lived a brief and active life in early 20th-century Moscow. The one on the left is a fake.