What does it mean in Mulan's poem (such an intertextual sentence)?

Open my East Pavilion door and sit on my West Pavilion bed. This means opening all the doors and looking at all the furniture in the house.

The general died in battle, and the strong man returned in ten years. Many generals and brave men died in battle, and the rest returned home in triumph.

These sentences are true, not intertextual:

Twelve military books with the names of lords on them.

Go back to see the son of heaven, and the son of heaven will sit in the hall.

When you go out to meet your partner, your partner is depressed.

Intertextuality, that is, "intertextuality", is a special rhetorical device in ancient Chinese. Contextual meaning interweaves, permeates and complements each other to express the meaning of a complete sentence.