On the day his portrait was unveiled, Pace fell into a contemplative state of mind that mirrored the moody portrait. “I certainly made some wrong estimates,” he said at the 2009 ceremony.

Toward that end, it has announced its acquisition of Édouard Manet’s “Portrait of Madame Brunet,” a prime-period, nearly full-length portrait made in the early 1860s. This portrait of a ...