The "fullscreen" screen area is the 16:10 that results from subtracting the notch height. The area left and right of the notch is strictly for the menu bar and

The "fullscreen" screen area is the 16:10 that results from subtracting the notch height. The area left and right of the notch is strictly for the menu bar and will be blanked out on video or full-screen apps. I guess that if you auto-hide the menu bar, a black strip will mask the area.