I'm confused

What confuses me is the meaning of visual line of sight. Specifically, do I need to keep eyes on the drone at all times? And if I'm not looking at the drone do I need an observer who is?

If the answer is yes, that would make videography impossible.

My experience has been that if I avert my eyes from the drone to compose and shoot my video, it's real difficult to catch sight of it at any distance greater than 1,000'.

Hi, it depends on the situation and the place, if there are obstacles around it is better to keep an eye on the drone and film continuously (that's what I do) if it's a clear view without obstacles an eye knew the drone an eye on the screen also depending on the situations. Personally I look at the screen only when I have to move the gimbal to find my proper angle.
For the movements of the drone I prefer to watch it once the gimbal position according to my desire.

The rule is in place to basically remove any risk of hitting anything or anyone. Fly with common sense and you will be fine. It's why things like FPV flying are illegal here (at least without a spotter). You are looking through goggles instead of the drone. I'm not sure on the law in the US regarding FPV.

Hello there Tandemist. Thank you for reaching out and for the information you have shared with us. Being able to actually see your drone,  without the use of any visual aids, binoculars is considered as Visual Line of Sight ( VLOS ). If you can not longer see the said drone in flight, that is simply beyond your VLOS. I would highly recommend to follow the rules and regulations when flying your DJI Drones to avoid an untoward incidents. In addition, I will post a DJI Forum link where in you can learn more about this matter. Thank you and have a safe flight always.  

https://forum.dji.com/thread-220261-1-1.html