LAS VEGAS—When Vermeer's circa 1670 painting A Young Woman Seated at the Virginals sold for $42 million last year at Sotheby's London it was the first Vermeer to come on the market since 1921. Market observers had already begun attributing the purchase to Las Vegas property developer Steve Wynn. According to a recent report in The Artnewsletter, published by ARTnews magazine, they were right. This week Wynn will put the painting, which until recently was on loan to the Philadelphia Museum of Art, on view in his new Wynn Las Vegas resort gallery that opens Thursday. The Vermeer, which measures a mere eight by ten inches, will hang alongside other works from Wynn's collection, which includes notable pieces by Picasso, Renoir, Monet, Rembrandt and others.