The first section of the BFR being assembled by SpaceX
That photo shows the inside of the mandrel, which is the form they're using to make the BFR's fuselage (from carbon-fibre type composites). It's not flight hardware or part of the BFR itself. It's also the largest such mandrel in the world - bigger than Boeing's similar one for making Dreamliner fuselage sections.
Biting the hand that feeds IT
