"The world of construction seems to be the most tangible, and therefore final. This made me nervous. I started to wonder if it were really so. Isn't a construction a beginning of a thing like a seed? Isn't it a segment of a larger totality, like an elephant's tail? Isn't something just about to emerge not quite structured-never quite structured....like an unfinished church with a sky ceiling?" YOKO ONO, around 1966.
This really got me thinking. Tangible is final if you think about it. Done. Finished. No more. I can totally understand how an artist would like to play around with this concept in their work. Making work that requires the viewer to use their own visual library to construct an image from a fragment that they may or may not recognize. Here are some examples that Yoko Ono uses

Smoke Painting
Light canvas or any finished painting
With a cigarette at any time for any
Length of time
See the smoke movement
The painting ends when the whole
Canvas or painting is gone.

Painting for the wind
Cut a hole in a bag filled with seeds
Of any kind and place the bag where
there is wind
As you can see these frank ideas are very intellectual and require a certain amount of positive energy from their viewers. But what I love about this kind of work is that it is my believe that it accomplishes exactly what it was created for: What is our concept of art as artists, and how can we manuever it into a new and original way? Shock, controversy, I think that truly original work will require these elements.