Current trends in technology-enhanced learning highlight the increasing importance of mobile digital tools in learning scenarios; seamless learning, or learning that spans contexts and activities within and without the classroom, is becoming mainstream. Despite the growing body of the literature in this area, this chapter highlights a general focus on technological issues and perspectives and a lack of theoretically driven discussion. We argue that theoretically/conceptually inspired literature reviews covering pedagogy and cognitive aspects of learning are currently needed to establish a grounded framework for future research in this area. This paper contributes one such analysis—it proposes and reflects on the issues raised when considering seamless learning from the perspective of the established literature on external representations (ERs), a core concept in distributed or embodied accounts of cognition. Core issues we discuss are: (a) what are the challenges facing seamless learning from an ERs perspective? (b) how can knowledge about ERs be applied to seamless learning systems?, and (c) what methodological challenges will emerge if seamless learning systems are studied from the perspective of ERs? This discussion is intended as a bridge between practical and applied work in seamless learning and theoretical or laboratory-based work in ERs—it seeks to drive the field of seamless learning forward by highlighting best practices from an established theoretical perspective. By elaborating on a theoretically grounded lens, we seek to empower researchers to identify promising approaches for the design and evaluation of next-generation high impact seamless learning solutions. © 2019, Springer Nature Singapore Pte Ltd.