Dell P3424WEB User Manual page 12

15 Camera Shutter
Close/Open
12 | About your monitor
Rotate clockwise to close camera shutter. When
closed, the camera will replace the image with a black
pattern.
Rotate counterclockwise to open camera shutter.
When opened, UC applications can open camera
function to use the camera when it is needed.
NOTE: The close camera shutter is different from
the disable 'Webcam & Presence Sensor' in OSD
menu. Disabling 'Webcam & Presence Sensor' will turn
off the whole webcam module, hence webcam and
sensor will not appear in the system.