https://twitter.com/jonostrower/status/1743466899869147549
Jon Ostrower
@jonostrower
According to that photo, it’s the mid-aft door that is missing. That door, for carriers like Alaska, is deactivated in the factory by Boeing before delivery. Passengers don’t even know it’s a door because it’s just a normal sidewall and window in the 737 Max 9 cabin
https://pbs.twimg.com/media/GDIJ57ybMAAXC49?format=jpg&name=large