@Ronnie 2¢: What a great question - and from the perspective of someone who was not actually there - completely reasonable. I'd hoped to write an expanded commentary on many of these images but just don't have the time these days. Here, we are standing on a balcony. The area in question is an opening to the main room. Walking in to this space one experiences the noise and activity of the vast building, so there is no illusion - as there most certainly is in the photograph. Good call!