I believe that "extension with a button" is for selecting Sport, Sport-Plus, and Normal modes, just like on a Ferrari. Notice that the Sport/Sport-plus buttons are missing from where they would normally be located on the center console.

I can't believe that with cars as personalized as these 911s, they still manufacture them with "buttons to nowhere" in the center console.

I'd get rid of the vertical gear selector and replace it with a round selector nob like on the Jaguar so you can see all the buttons on the center console and not have the gear selector block you view of buttons on the passenger side of the center console. It would make for a sleeker look.

The center stack looks odd now with all that empty space, hopefully they will move some other buttons down there to fill up some space