First the device must be squeezed gently to let the partner know that you are thinking of her/him, and it then responds with a slight glow as a sign of initial. The user has to blow into it and create a "message" in the form of an animated light sequence as the device responds to the breath. When relaxing the grip, the message will be sent to the corresponding Communicator. The remote unit indicates that there is a message but waits until its owner squeezes it to play back the light sequence.
Source: Buchenau, M. and Suri, J. F. 2000. Experience prototyping. In Proceedings of the Conference on Designing Interactive Systems Processes, Practices, Methods, and Techniques (DIS’00). ACM Press, 424–433.
