If you think about it though... even the things we discuss as spoilers we know nothing about lol.
The head was one of the first things shown... what is it, what does it do? The urns... obviously they open... the are green cylindrical things inside, they also have moving oily stuff on them. How do they work, what are there purpose... I could go on and on, the things we have seen are still mysteries to us.
I keep reminding myself that as a director why would I give away all my secrets, especially if I kept a tight lid on everything... I wouldn't. I would tell my marketing crew to screw with the fans and give them things that will make them think they know something, so I can show them how little they knew during the movie.