This study seeks to decipher the modus operandi of Shanghai’s image portrayal to the audience through social media platforms, particularly Twitter. Leveraging the potency of big data analysis, the study scrutinizes the applicability of the two-step flow communication model in the communication of Shanghai’s image. The findings highlight the cardinal role of opinion leaders in the image communication process, overshadowing the impact of mass media. The age-old phenomenon of two-step flow, wherein information trickles down from mass media to opinion leaders, appears to be fading away. Although mass media’s tweets can potentially reach a broad audience, they do not necessarily captivate the attention of opinion leaders. Thus, the study underscores the importance of both mass media and opinion leaders in shaping Shanghai’s image.