“Where might you expect to find William Hogarth’s fine and recently restored portraits of William and Elizabeth James, or a lobby-filling Roman floor-mosaic from Antioch that depicts a lively lion and antelope hunt? Or Otto Dix’s painting of a pregnant woman, which has its own visitors book nearby, so that people can record their usually extreme reactions to it?” Worcester, Mass., that’s where. Says director Matthias Waschek, “The big problem we have is that the collection is outsizing its city.”