This qualitative study examined a group of 41 bilingual preservice teachers who participated in a multi-year professional learning course lab project. The project implemented the change laboratory (CL) methodological framework during the same semester that the participants were teaching students in their field placements. The data analyzed for this study were obtained from one CL session of a Play-Doh activity, which was conducted across three cohorts. The narrative research methodology was employed, applying the lens of social imagination to analyze the data. During the activity, participants used Play-Doh to construct their visual narratives collaboratively and individually, presenting emic beliefs and desired practices as related to teachers' personal theorizing, highlighting bilingual preservice teachers' own cultural ways of being, knowing, and doing from their transnational communities. The findings indicate that art-mediated visual narratives can aid bilingual preservice teachers in materially and symbolically developing their professional agency. Implications for the role of art mediation in teacher education research are also discussed. By collectively understanding these personal and professional transformations, bilingual preservice teachers validate their experiential reality and establish co-mentored learning sources for one another, changing mainstream teacher preparation practices in predominantly White postsecondary contexts.