On the physics, marble on the legs and torso seem quite dense where they connect to the pillars, and also the base seems complete and flat, the three likely causing enough pressure for the center of the piece to not be crushed under its own weight.
User thinkyfish in another comment also mentioned the cloth at both ends of the hammock are solid stone too, adding even more resistance to the sculpture. Fantastic work not just in beauty, but engineering too.
On the physics, marble on the legs and torso seem quite dense where they connect to the pillars, and also the base seems complete and flat, the three likely causing enough pressure for the center of the piece to not be crushed under its own weight.
load-bearing dangly arm
User thinkyfish in another comment also mentioned the cloth at both ends of the hammock are solid stone too, adding even more resistance to the sculpture. Fantastic work not just in beauty, but engineering too.