Royal Presence
Q: Perhaps I am still new, and dealing with such things on a personal level, but I find myself struggling with such things as bowing to empty chairs, as I feeel that it is only when they are full that they are infused with that authority.
A: We bow to the thrones, whether occupied or not, because they are the enduring symbol of the head of the Kingdom. Just as when one salutes an Officer in the military, you may or not be showing respect for that officer, but you are showing respect for the rank that officer holds.
The Thrones represent the Royal Presence even if they are empty at the time. As such it is accepted that when one passes they Royal Presence that they will make a small reverence even if no Royalty is seated at the time.
Royalty also have an area around them known as the Royal Presence. This is an area you don't enter without permission. The size of this presence varies depending on the class of the royalty. In general the Royal Presence extends about 3 meters in front of the Thrones and directly in front of Their Majesties/Highnesses - seated or not. It is also considered poor ettiquite to block the line of sight of Their Majesties/Highnesses.
Generally, do not block the view of whatever event Their Highnesses are watching, and if you have to pass through this space, make a small, quick reverence. Also reverence the Thrones if passing within about 3-5 meters (seated royalty or empty) and if there is a high table at a feast make a reverence as you pass in front.
If Court is in session, the Presence is normally extended to the back of the Court. The area about 3 meters in front of the thrones should be clear, as well as an aisle up the center. One should stand up when Royalty processes to and from Court, and you should make a reverence as they pass.
When one is called into the Royal Presence, make a reverence as you approach. Kneel on the cushions provided, and when you leave make a reverence, and back up a bit, then turn to go. (one is not required to walk backwards the entire length of Court.)