The unexpected objects provide the viewer with a sudden and refreshing moment.
For example, when birds fly away simultaneously all of a sudden from a place they are perched on, it is like your mind becomes empty and thoughts stop for a moment and for that instant you become a new person. At that point the world looks completely different from the previous second. 


It appears to me that modern societies are building too many new buildings which ultimately might end up as surplus. I believes the next step for architecture is to try to create alternative spaces without buildings. An art project can offer a new perspective on existing places and provide an opportunity for imagination to create space in a new way. Beautiful and useful spaces may already exist and we may not notice them unless the opportunity or occasion arises. It is like a gateway to another dimension.