This is a Marble Boat, a favorite of the Dowager Empress. Lackeys rebuilt the Summer Palace in an effort to please her or at least gain her favor. They would extort money from wealthy people by saying the funds would go to rebuilding the Chinese Navy (destroyed by the Japanese in the late 1800s) and then use the money for rebuilding the Summer Palace. The Dowager Empress so loved this place, she would bestow favors on those who tried to undo the damage of the rampage of 1860.