What does it mean that my female colleague asked me to send her a hairpin?

If it is a friend, it is a joke. Don't take it seriously

If you are not familiar with it at ordinary times, you are a bitch. Ignore her. Some women are like this. When they meet everyone, they always feel attractive.

People joke and tell you that you really bought it for others, but they treat you like a big head. There is no other way.

If you like her, then I suggest that men be flexible and not give it to her this time. If she asks you, you don't have to remember. Then find an excuse to make amends and invite her to dinner, and then give her the hairpin you bought in advance when eating, thus achieving the expected effect.