Military Parade, North Korea

The Left is to the left the Advance (similar to a ship's port.)
The Right is to the right the Advance (similar to a ship's starboard.)
If the Advance is changed, then all other directions are changed to be based on the new Advance.
There is only one person in charge a parade at a time. Changing this person is very ceremonious. This is to make it obvious to the soldiers who is currently in command and therefore to whom to pay attention.