Where has David been hiding?

It is likely the cloaked figure is now David for certain...  i am 85% certain on that...  but we dont know when this scene happened... it could be at the hands of David.. or he arrives in the aftermath ... who knows..

As for the image, this is taken from Spaights Alien Engineers Concept work inside the Cave System, and so its nothing to do with David.

But indeed the Big Heads make a return, i am not sure they would in any Cave System though.... but certainly in the Temples and outside.

In Spaights draft  the Cave System had many Holes like this and they was part of a underground Cistern  Water System, and has to do with the Terra-forming of the Caves.

David may have taken what he could use from the ship and combine with whatever he could use in settings like posted?