It’s titled “Unmanned Drone.” Walker completed it in 2023, though its constituent parts are much older: They belonged to a monumental equestrian statue of the Confederate general Stonewall Jackson, which stood for a century in Charlottesville, Va. After the “Unite the Right” rally of 2017, which began with neo-Nazis marching with torches and ended with a woman’s death, the City Council voted to bring the statue down. There were hearings. There were lawsuits. Walker got her hands on it almost five years later.