Professional development programs today increasingly ask teachers to capture video in their own classrooms to share with peers. Yet little work has explored the nature of the videos that teachers produce for this purpose. This study takes a first step by looking inside a set of almost 200 videos collected by 84 K-2 teachers participating in one of two online mathematics professional development modules. Our analyses reveal that, overall, teachers collected video excerpts with good video and audio quality. In addition, the videos focused primarily on students and provided a great deal of access into student thinking through student talk and gestures and, to a lesser extent, the use of physical manipulatives and drawings. While previous research has suggested that teachers might think that videos excerpts of their classrooms should serve as exemplars of teaching, in this dataset, nearly 25% of the videos depicted students struggling with the mathematics they were exploring, and more than 30% highlighted mathematical errors that students made as they worked on the given task. We offer reflections on these findings and raise questions to be explored in future research.