This article examines the characteristics of meaning-making during classroom discourse using data from a study regarding a yearlong teacher professional development (TPD) program intended to promote dialogic discourse in whole-class practice. The in-depth, video-based case analyses of two whole-class discussions in history classes (two classes/teachers, N = 46 students) at the end of the TPD integrate multi-semiotic and content-bound perspectives. The analyses show how the students adopt an active role in shaping the dialog and contribute to the direction of the discourse, while both teachers assume a moderating stance. Concurrently, the findings highlight the inherent tension teachers face while ensuring student participation and compliance with disciplinary norms. In addition, the results reveal new student roles and asymmetries due to altered responsibilities in student-owned classroom discourse, which are particularly elucidated through nonverbal interactions. This contributes to existing research by highlighting novel, critical elements for consideration in TPD.