The workshop by Marc Rettig and Hannah Du Plessis on April 13, 2017, focused on the themes of participation, reconnection, and design within the context of the interaction design community. It emphasized the importance of awareness and critical reflection on the consequences of design choices and encouraged participants to engage in meaningful conversations about industry challenges and opportunities for positive change. The document also highlights various strategies and methods to foster collective participation and systemic transformation in response to current societal issues.