Mark Templeton, who's got the 3rd Model X ever made (Elon Musk got the 1st one!), explains to a very curious young lady how the Falcon wing doors work. The sensors detects when a person is nearby ... so Mark is not hit by the door, even if he's very close ... except his glasses!
Very good explanation of the difference between GULL WING doors and the FALCON WING doors!
VIDEO: MODEL X FALCON WING DOORS EXPLAINED BY MARK TEMPLETON