I watched them build a box. It had an opening or doorway and detail was applied to the walls inside. Detail was also applied to the outside walls of the box. I thought, "But it's a set. What type of little room needs the interior and exterior of the walls detailed?" Then I watched as they put the top with a round translucent dome on. Now I am watching them put a similar shaped platform a foot or two above the floor in tall thin set. This platform has a hole in it for (drumroll) someone to climb up through.
Characters are in an elevator.... they probably enter it from the set that they filmed on the first day (elevator loby/hallway).
The elevator stops.
The occupant(s) climb out through the hatch in the top.
Will it be Obi or Ani....or both?!