Online photo sharing and the associated engagement from other users, defined as number of likes and comments received for a post, is a key function of modern social media. However, little is known about emotional responses of social media users to the received engagement, and how such responses might drive social media photo sharing. In this study, we present a model of emotional mediation of the effects of social media engagement on posting frequency and content change. To test our model, we conducted a within-subject online experiment with 248 social media users. During the experiment, the participants were exposed to three conditions following a photograph sharing scenario: their usual pattern of engagement, more engagement than expected, and less engagement than expected. In each condition, the participants reported their emotions, estimated the time until their next post, and chose a photo for their next post. The results of the study indicated that high-arousal positive emotions mediate the effects of more engagement than expected on posting frequency. Both high-arousal and low-arousal negative emotions mediate the effects of less engagement than expected on content change. The practical implications for creating effective social media campaigns and improving user experience are discussed.

在线照片共享和其他用户的相关参与（定义为帖子收到的点赞和评论数量）是现代社交媒体的一项关键功能。然而，人们对社交媒体用户对收到的参与的情绪反应以及这些反应如何推动社交媒体照片共享知之甚少。在这项研究中，我们提出了一个关于社交媒体参与对发布频率和内容变化影响的情感中介模型。为了测试我们的模型，我们对 248 名社交媒体用户进行了一项主题内在线实验。在实验过程中，参与者根据照片分享场景暴露于三种情况：他们通常的参与模式、参与度高于预期和参与度低于预期。在每种情况下，参与者都报告了他们的情绪，估计下一个帖子的时间，并为下一个帖子选择一张照片。研究结果表明，高唤醒的积极情绪介导了比预期更多的参与对发布频率的影响。高唤醒和低唤醒的负面情绪都调解了参与度低于预期对内容变化的影响。讨论了创建有效的社交媒体活动和改善用户体验的实际意义。