Well, raising eyebrows together refers specifically to couples. It is used to describe classmates who are wrong. It can be changed to unity and friendship.
Lifting the case to the level of the eyebrows means raising the tray as high as the eyebrows when serving food. Later, the couple described each other as respectful and loving. From "The Book of the Later Han Dynasty: Liang Hong's Biography": "When I rent a pound for others, every time I return home, my wife will use it as food. She doesn't dare to look up in front of the pound. She raises the case and raises the eyebrows." Lifting the case and raising the eyebrows is a special word to praise a happy marriage between husband and wife. Heart to heart, we respect each other as guests, and the husband sings and the wife follows.