My experience pre-full screen on macs was that the green button would do just about any random thing except make the window fill the screen. It would certainly

My experience pre-full screen on macs was that the green button would do just about any random thing except make the window fill the screen. It would certainly change, usually it would fill vertically (but not always) but almost never horizontally. To this day I still rarely press that button because of years of it doing nothing but unpredictable nonsense.