Mirror surfaces are part of our everyday life. Among them, curved mirrors are used to enhance our perception of the physical space, e.g., convex mirrors are used to increase our field of view in the street, and concave mirrors are used to zoom in on parts our face in the bathroom. In this paper, we investigate the opportunities opened when these mirrors are made dynamic, so that their effects can be modulated to adapt to the environment or to a user’s actions. We introduce the concept of dynamic mirror brushes that can be moved around a mirror surface. We describe how these brushes can be used for various optical manipulations of the physical space. We also present an implementation using a flexible mirror sheet and three scenarios that demonstrate some of the interaction opportunities.