When designing visual content in user interfaces, it is crucial to recognize that the choice of the representations used to display information and concepts plays a critical role in how we perceive, interpret, learn and reason about these information and concepts. Humans are visual creatures: we spend most of our day deriving meaning from what we see. The rich stimuli that we process within fractions of a second using vision becomes information which serves many purposes in everyday life, from mundane activities such as identifying whether an object is one we can lean onto when we need a pause, to complex intellectual tasks such as making sense of a large amounts of multivariate data. In this talk, I will present my reflections on why choosing appropriate visual representations in user interfaces is such an important design decision to guide and empower people, and how easy it is to underuse or misuse their power. Drawing on projects in visualization and creative authoring from my research group, I will discuss the many roles that visual representations -- from navigation widgets to data views -- can play on how we interact and reason with computing systems, and the impact on users' creative and analytical tasks.