In that (quite interesting) post the author frequently wonders "WTF were they thinking?". E.g. did they think we would not notice that the screens on all the computers on both floors were identical?
My wife is from China where not so long ago everthing was identical, down to the progaganda art on the wall. Her immediate answer when I asked her was "duh, they don't care what the delegates thought, the whole exercise is to show pictures to the local NK population about how the great foreign technical leaders liked the NK technical office".
I think we tend to forget that: it isn't the delegates that Pyongyang is afraid of, its their own people.