This study achieves two objectives: (1) define two specific affordances—affective embedding and rendering—capturing the connection between affect and social media affordances from the perspectives of designers and end-users, and (2) examine the mobilization of affective reactions with an emphasis on the intersection between affective affordances and the networked status quo. A sample of 253,489 Facebook posts that contained key terms related to climate change is analyzed using a series of log-log models to examine the mobilization of affective reactions. We argue that possibilities for rendering affect using the Facebook reaction menu are nested within affective embedding and general platform affordances. Empirical analysis examines a two-step logic where the networked status quo determines content exposure, leading to content replication. Although affective reactions are primarily driven by content reach, the analysis reveals variations among six types of Facebook pages in terms of how their prominence contributes to generate affective reactions among audiences.