1, left flag and right drum refers to the fact that in ancient wars, the army set up battle flags and drums on the left and right sides of a camp or castle to direct the army's actions and transmit signals.
2. The front tent and the back screen refer to setting tents as temporary residences or command centers in front of camps or castles, and setting screens as fortifications or bunkers behind them.
3. The shape of sleeping bow is to describe the appearance of this geographical form or architectural layout, similar to prone bow.