What does the asterisk key with white characters on the blue background in the lower right corner of QQ avatar mean?

It's Tencent's tim software. TIM is a multi-platform client application released by Tencent on 2011. TIM is a QQ with easy chat and convenient work. TIM supports collaborative office service on the basis of QQ light chat version, can log in with QQ number, fully synchronize friends and messages, support multiple people to edit Word and Excel documents online, and is more suitable for office users.