This gave the impression of a
ghost of one’s past-self occasionally being visible alongside
one’s current self, from time to time entering and leaving
one’s current body. Visitors were unable to predict exactly
what would happen next, or even verify what in fact they
had just indeed seen – the time-shifted overlays replaying
the visitor’s previous behaviours were intentionally
bewildering. Just when a visitor thought s/he had figured
out what the mirror was doing, the mirror’s behaviour
would change. In keeping with our previously identified
design sensibility valuing requisite unpredictability, we
hoped that this type of ephemeral, unrepeatable interaction
would engender enchantment and engagement through its
very mystery, and in addition, that the mirror would reward
extended investment with deepening knowledge. Visitors
who persisted in exploring the mirror’s functionality could
learn to react to and exploit the layering algorithms to
produce pleasing visual effects.