A disruption of space that images an alternative reality or utopia, at least temporarily. These actions give a glimpse of “the world that is possible” by modeling it, earnestly or in jest. For example, Monthly Critical Mass bike rides prefigure a possible city in which bikes are the predominant mode of transportation. Similarly, many Civil Rights era protests could be said to be prefigurative, modeling a world without segregation by acting as if the laws did not apply.
Pranks, art interventions, tactical media, alternative festivals and temporary communities, even electoral guerrilla theater, can also be effective ways to prefigure the world we want to live in.
Prefigurative interventions are direct actions sited at the point of assumption — where beliefs are made and unmade, and the limits of the possible can be stretched.
Source: http://beautifultrouble.org/tactic/prefigurative-intervention/