What does it mean to send fans during the Spring Festival?

If you are a bamboo fan and a friend, you may be an ancient scholar, who often uses plum, orchid, bamboo and chrysanthemum to express his lofty and free from vulgarity, or as a warning to his character.

Or a fan is a tool to cool off the wind and is a "cool friend".

A fan with good appearance can be worth tens of thousands of dollars. If you send this kind of fan, it is obviously a euphemism to please flattery with "elegance".