The word “si xiang jia” is a homonym with "thinker" in Chinese and means literally a "person of private enjoyment." But it actually refers to people who pursue health, leisure and an independent lifestyle.
They have their own ideas, pick their own place to stay and share leisure time with family and friends, but always keep some time for their own. They also tend to maintain a place of privacy in their heart and try to "privatize" their enjoyment.