1930s Afternoon Tea and Cosmopolitan Shanghai
The meeting of intellectuals in tea houses under the protective cloak of International Settlements was an example of the private and exclusive nature of Shanghai's tea houses. While tea houses in Beijing and Chengdu were important social meeting places, open to all and roughly egalitarian, in Shanghai, tea houses began to develop into more exclusive venues. Here tea houses became the de-facto meeting point for eloping lovers and surreptitious conversations, a private place where men and women could meet clandestinely and plan their escape (and escapades); so common was this practice that the phrase "when a woman wants to elope, more than most use the tea house to send them off". In these private havens, one could partake in coffee, as well as 'European-style' tea served with milk and a tradition of Western-style tea and coffee houses emerged.

1930's Nanjing Road, Shanghai, Wikimedia
Nobody embodied this strange mixing of eastern and eastern-inspired western traditions better than Zhang Ai Ling, the iconic Shanghaiese female author, who preferred to take black tea with milk and revelled in these Western-style tea houses, that she found intellectually stimulating. The emergence of these 'tea salons' demonstrate the hybridised nature of some tea houses in Shanghai during the 1930s. During this era, Shanghai was at its most cosmopolitan, reflected in the emergence of 'hai pai' (which became known as Shanghai style) as a symbol of refined, bourgeoisie and luxury, an aspect of local culture keenly articulated and embodied by Zhang Ai Ling.

Zhang Ai-Ling, Baidu
More deeply, this hai pai culture reflected an openness to, and an ability to embrace foreign culture and incorporate into local traditions. Therefore, this refined and elegant 'hai pai' became an important motif in the development of a local Shanghaiese culture unencumbered by the influx of foreign customs and traditions. The best opportunity to sample this uniquely Shanghaiese tradition is in the Chartres Restaurant located in the Former French Concession, on West Fuxing Road.
Picture source: https://upload.wikimedia.org/wikipedia/commons/f/f5/1930s'_Shanghai_Nanking_Rd.jpg
Additional sources of information
Pinterest: https://uk.pinterest.com/tiffanytong/1930s-shanghai/ - Collection of 1930s Shanghai pictures.
Shanghai life of Zhang Ai-Ling 张爱玲 (Eileen Chang): http://www.zhihu.com/question/23782101 - Chinese