The tower floors are most likely hung rather than held--so each floor will be a cantilevered off of a super massive concrete and steel support column. Imagine that behind the facade (which tricks you into thinking the floors are solid and resting on each other) there is instead a little suspension bridge, and the floors are all hung.

It's not at all even slightly creative, and it's not even that difficult to accomplish, architects cantilever shit all the time. It's a practically a fetish for architects now.