(1) The document discusses the role of performance in interaction design work. It argues that performance, such as client meetings and presentations, is a central part of a designer's job and should be considered "real work".
(2) The author observed designers at work and found that product development involves careful staging of meetings, skillful roleplaying to envision how users will interact with a design, and using these performances to build consensus and make collaborative decisions.
(3) Through analysis of video examples, the author illustrates how designers take on different roles like user and client to perform prototypes and gain understanding of designs from multiple perspectives. Performance is a key part of envisioning, refining, and bringing designs into being.