Using videos as tools for reflection has a strong grounding in the research literature. Traditionally, these videos provide representations of K-12 students interacting with one another and their teacher during small or whole group instruction and come from teachers' own or their peers' classrooms. More recently, online simulated classrooms have been used as practice spaces to support teachers in learning how to engage in core teaching practices, such as facilitating discussions. The purpose of this study was to explore the potential usefulness of video records generated from online simulations as a tool for self-reflection. To do so, we examined the nature of in-service elementary teachers' self-reflections from video records of them facilitating argumentation-focused discussions with five student avatars in an online simulated classroom. Findings suggest that most teachers' reflections on their discussion practice tended to be positive in nature. In addition, findings suggest that most in-service teachers used multiple pieces of evidence to justify their overall quality assessment of their discussion on five key dimensions of argumentation-focused discussions. The types of evidence they used were aligned with how a scoring rubric defined these dimensions but varied in nature across the participants. Finally, findings show that study participants tend to draw upon both what they and students say and do during these discussions as evidence to support their overall assertions about how well they attended to specific discussion dimensions. Implications for using videos from online teaching simulations as tools for reflection are discussed.