I mocked up a couple diagrams for a
twitter thread showing how the building widens as it increases in height.
In the first, you can see how the NE corner columns "step out" a few inches compared to the one below (magenta lines) relative to the grid lines. Whereas the next column stack is perfectly alighted (green dots) with the grid line.
For this one, I overlaid two floor plates - one lower floor and one upper. I turned the opacity of the upper floor down and you can see how the rounded corners stay in alignment while the pointed corners pivot outwards while elongating the curved radius of the curtain wall