The contrast between the 17th-century old master and 21st-century disrupter couldn’t have been more extreme. To the left, Rembrandt’s broodingly introspective “Self-Portrait With a Red Beret.” To the right, behind a protective glass screen, Banksy’s “Girl With Balloon,” the painting that had made global headlines when it sensationally self-destructed at an auction. Its frayed canvas now dangles limply below its elaborate gold frame. Retitled “Love Is in the Bin,” the ...