Your photo shows 2 hallways that are covered in plywood, not a balcony.
that means it is WTC 2 not WTC 1 as the silhouette photo shows. No agent, the top portion is not finished on WTC 1 so those are not hallways left and right of center. WTC 1 has a single hallway as the completed lower floors show.
BTW, your "core columns would be in the middle of the floor space seen.
The image is WTC 2 on the top floor and that the concrete core stopped on that side below the top for tourist purposes. There is a bank of elevators below that flooring. WTC 2 did not have the antenna and had no real need for the concrete core walls at the top.
Another aspect is the length and the sunlight. We are looking at over 100 feet. If that was WTC 1 it would have to be the north or the south side and at sunrise of sunset when the light and sky would not be that bright and the light would not be reflecting off the floor.
As it is, it is the west side of WTC 2 with its north and south oriented long axis and taken perhaps in late morning or eary after noon.
From your link.
Ms. Nanninga said, ''we have no reason to believe it didn't happen.
I have shown reason to believe it did not happen, or at least NOT where the article says it happened.