In the vision of ubiquitous computing, users are imagined as evolving in various, changing and not always foreseeable environments, in which platforms may arrive and disappear in an opportunistic manner. As a result, there is a need for User Interfaces (UI) to adapt to their context of use (<User, Platform, Environment>) while preserving usability. This capacity of UIs is called Plasticity. In a forward engineering approach, UIs are designed step by step starting from domainbased descriptions (user’s tasks and concepts) t o code. It is now well understood that plasticity may impact UIs at any level of abstraction. This calls for keeping the UIs design rationale alive at runtime. As models are practiced since a long time in Human-Computer Interaction (HCI), this paper investigates to which extent Model-Driven Engineering (MDE) is relevant for plasticity. UIs are designed as a net of models that define different perspectives on a same UI (user’s task, domain, concepts, widgets, etc.). The net is alive at run-time and transformed when the context of use changes. Transformations are performed with respect t o usability. This paper sketches the vision on a small running case study. It highlights a set of strengths and doubts that give rise to many perspectives.