What does feng shui mean by saying that closed doors are deep mountains?

Feng shui pays the most attention to the gas field. Houses take the gate as the vent (including modern balcony French windows, etc.). ) to absorb auspicious breath, just like a person's mouth. Therefore, it is very important to absorb the aura in Feng Shui. In modern times, it is not advisable for some people to close the balcony for petty gain. Because in the case of closed doors in modern society, closing the balcony again will break the hub of exchanging gas fields with the outside world and close the house. It's a deep mountain, that's probably what it means.