Acute crisis events ranging from natural disasters to terrorist incidents now tend to generate an almost immediate response from social media users. This is especially pronounced on Twitter, due to that platform’s specific affordances as a particularly open and real-time medium. While analyses of such events have increased over recent years, we still understand relatively little about the way in which audiovisual materials relating to such crises are circulated and what they contribute to processes of witnessing. This is important, however, in an increasingly visual age when audiovisual material tends to be more widely viewed and shared than plain-text updates, and thus has a greater potential to influence viewers’ interpretations of an event. To address this gap in our understanding, this article investigates the distribution dynamics of audiovisual content on Twitter in the immediate aftermath of terror attacks in Paris and Brussels. Results point to the importance of broadening conceptualisations of conflict-related visuals and the ongoing relevance of affective content in such material. Furthermore, this article argues that contexts of time and space are crucial to consider, as is the role that individual actors – both human and non-human – play in disseminating such content.