[Ned.B]

I think if viewed from above it would look more regular than it does from this angle. Looking at the ground floor plan the 6 in the center (3 across and 2 back) are the core, three to the north of that and along the west side are the tower exterior columns. The two columns aligned with the south edge of the core to the east and west each appear to be resting upon 4 piers, this as Briguy suggests could definitely be due to the cantilever. I'm not sure what the one piers south of the core is that isn't aligned with anything but I suspect it has to do with not being able to place piers directly abutting the adjacent building and is taking some of the load from the south edge of the building.

It's a tight site with some structural acrobatics, and residential buildings tend to not be quite as structurally regular as office buildings, so the foundation configuration is going to be less regulated than we are used to seeing.