To me, the official documentation is your screenshot of 'How to Install Security Mount’ (but your YouTube video doesn't mention it either). Step 3 makes no mention of the screen.
I tried using the screw as per your photos, but the camera and mount seemed to be more secure without it.
I think this is my next question.
What benefit does it serve?
Reolink have obviously gone to a lot of trouble to provide the screw and how it connects the camera and the mount?
As you can see the screw is only 7mm (0.28 inches) in length.
The screw is silver.
Without taking down the camera and unscrewing the camera from the mount I cannot show you where the screw goes, but the mount has been specially designed for the screw to go into a hole.
It's not a huge concern but I wondered why it is not mentioned in the official documentation.
Thank you for reply.
When I mentioned the lock screw, it is a little silver screw and there is a hole for it to be inserted and then the screw tightened.
I haven't seen any mention of this screw in the documentation and your Reolink YouTube video (https://youtu.be/01ptIq0551o) doesn't show it being used.