Why don’t candidates salute at the altar when re-entering for the Middle Chamber Lecture and Raising?

The physical rooms in which we hold our meetings represent various things for Masons. Most often they represent the “Symbolic Lodge” that is invoked when we perform the Ritual of Opening, and we are taught to salute the Master on entering or retiring from that Symbolic Lodge. But sometimes those same rooms represent something else for us. For the Middle Chamber Lecture and the Raising the room represents the grounds of King Solomon’s Temple rather than a Symbolic Lodge, and as a result the candidates do not salute when they enter.