\"Which brew are you going to choose?\": an interactive 'tea-decider-er' in a teahouse shop window

We describe the design of an interactive shop window created and installed for use in an independent teahouse. Using cameras to track the gestures of customers on the street front, the system allowed visitors to interact with an animatronic character who helped them choose a 'brew' from over 80 unusual tea varieties. In this paper we describe how we worked with the business owners, observing their practices to develop an understanding of how they helped customers choose one tea out of a large array of appealing possibilities. We describe the design process we undertook when creating the window, and examine the functional, aesthetic, technical and commercial factors that pose challenges when creating a bespoke piece of interactive art for a functioning real-world business.