Reflective practice is essential for supporting learners in addressing complex, ill-defined problems, yet its developmental processes in digitally mediated, collaborative environments remain underexplored. This study examines how Padlet supports reflective practice within a project-based design thinking course, using Schön’s theory of the reflective practitioner as the analytical framework. A mixed-methods sequential explanatory design was employed. Quantitative analysis of approximately 900 posts from 15 teams produced indicators of reflection quality—the Reflection Depth Index (RDI), Team Reflexivity Index (TRI), and Reframing Evidence Index (REI). Based on these patterns, two contrasting teams were selected for in-depth qualitative analysis. Findings revealed substantial variation across teams. High-performing teams demonstrated frequent dialogic and critical reflection, reciprocal interaction, and clear episodes of reframing. Low-performing teams showed predominantly technical reflection and limited frame revision. Padlet’s affordances— persistent visibility, spatial organization, and asynchronous interaction—enabled learners to externalize thinking, revisit earlier interpretations, and engage in reflective dialogue over time. Instructor feedback further supported reflection when actively integrated by teams. This study extends Schön’s theory by illustrating how reflective practice unfolds in digitally mediated collaboration and conceptualizing reframing as a gradual, iterative process. The results highlight design principles for reflective learning environments, including temporal space for reflection, explicit reframing support, and structures that promote team reflexivity.