On Sunday, Shanghai’s fashion set turned out to Central Studios, China’s largest commercial photography studio, for the Super Summer Fair. Now in its sixth year, the annual event plays host to pop-up shops, bars, food stands and DJs. The market also serves as a showcase for upcoming Shanghai designers as well as purveyors of vintage clothing and accessories, a growing niche in this city of more than 24 million. On the sweltering summer day, attendees dressed to beat the heat in shorts, T-shirts, overalls and summer dresses in florals and other bright patterns, paired with sandals and sneakers.