Although classroom video is well recognized as a valuable reflective resource for student teachers, we know very little about how university supervisors' pedagogical practices are shaped by creating and using videos with their student teachers. This study explored how 12 supervisors developed greater stances of inquiry toward their practices as they experimented with video and shared their experiences with peers. Patterns in project meeting and interview transcripts revealed how these experiences not only enhanced their existing personal approaches toward supervision and helped them "anchor messages" they wanted to communicate to their student teachers about teaching methods, but also challenged their roles as observers and prompted them to build messages about teaching dispositions directly from video. The findings show how a community of practice encourages supervisors to take considerable responsibility for their own growth as teacher educators and provides a coherent framework others can use to pursue similar professional development initiatives.