Earlier this month, the art world was caught off guard by news that Melissa Chiu would be stepping down as director of the Hirshhorn Museum and Sculpture Garden in Washington, D.C., to become the director of the Solomon R. Guggenheim Museum in New York. The appointment was a surprise because Mariët Westermann had only been named director of the museum in 2023, replacing long-serving Richard Armstrong. But it was decided that Westermann would become C.E.O. of the foundation that oversees all the Guggenheim museums—in New York, Venice, Bilbao, and eventually, Abu Dhabi. That created the need for the new position of a director focused on programming and fundraising for the all-important Manhattan museum.