Some examples of those interventions, for example the group of people that stops suddenly in a station in different body postures, the viewer is socked because it is not normal it is outside of the normal context of an station where everybody is hurry to take a train or a bus, the distraction can change some minds, can change the humor of an stressed worker or of someone that has lost the train.
Another example is the group of people that goes to the tube naked, it can cause the same effect of the last example.
Another example is the surprise produced by the fountains in South Bank during the summer, they have the shape of water walls that interact with the people provoking surprise and susto.

When there are used playful interventions to relieve stress, it is important the voluntary participation of the user, he/she decide to use the playful thing to feel better or generate abstraction from the reality.

But when the intervention is about to provoke a situation that produce an stimulus that has to overlap the previous stress situation, the distraction is produced without the consent of the user, the surprise effect is essential.
It is all about to design DISTRACTIONS (think in unexpected distractions, the surprise effect is essential) ,in different ways, and how these distractions can produce the re-interpretation of the reality by an individual or a collective of people affected by these. The distraction has the task to abstract the victim from his/her reality, worry, stress or crisis situation ( when a stress stimulus is used to relieve another crisis and make you wake up to balance the importance of your previous crisis situation).