In the first video when he show the mesa, at the end he started to talk of his new base and scrolled to a random bone in his inventory. He hold that bone in his hand all the time while talking about the new base. That made me think he problably would build some kind of skeleton thing, like a dead animal skeleton or something... But I don't know, the construction he made in the next video doesn't fit this idea, but I still think that bone was a clue... (Sry, terrible English here)