At the end of The Six Thatchers, Sherlock is having a therapy session. We get two angles at the room in which this is happening:
Unless I am very much mistaken, this suggests the following layout of the room (cross-section from the perspective of the second still):
I find this layout bizarre:
On a considerable length, there is a connection between the rooms that can only be crossed crouching.
Only one third of the room is used. As you want therapy sessions to be private, nobody can use the other segments.
Another bizarre aspect are the windows, which are almost based at ground level. This suggests that the room was once bigger and horizontally split, with the therapy happening in the upper part. But this still does not explain why the walls have not been extended to the ground.
My questions are:
Is this room really shaped like that or did I make a mistake?
Was this filmed in a real location or is this a set?
Either way: What are the reasons for this bizarre architecture?