What is the significance of China's ancient token of love to modern times?

It means: giving a token is like giving your wish, indicating that you will never change your mind.

In ancient China, engagement was an important social etiquette for men and women to determine their marriage relationship, second only to formal marriage. The betrothal follows "parents' orders, matchmakers' words", while adolescent boys and girls often use keepsakes to betrothal; Due to the ethical code and social pressure, the exchange of tokens of love is generally carried out privately between men and women, and others have no way of knowing it.