We propose residUUm, an audiovisual performance tool that uses sonification to orchestrate a particle system of shapes, as an attempt to build an audiovisual user interface in which all the actions of a performer on a laptop are intended to be explicitly interpreted by the audience. We propose two approaches to performing with residUUm and discuss the methods utilized to fulfill the promise of audience-visible interaction: mapping and performance strategies applied to express audiovisual interactions with multilayered sound-image relationships. The system received positive feedback from 34 audience participants on aspects such as aesthetics and audiovisual integration, and we identified further design challenges around performance clarity and strategy. We discuss residUUm's development objectives, modes of interaction and the impact of an audience-visible interface on the performer and observer.