An artwork is interpreted through the eye of the artist. Some art may be done with intention such as, Georgia O'Keeffe and her flower paintings. Other artworks may be representational, like Alberecht Durer did with The Four Horsemen of the Apocalypse, a depiction of the end of the world as you know it. Art does not have to be intentional and representational to be considered art. Major abstract pieces such as, the waterworn pebble that resembles a human face may cause people to be hesitant on whether this pebble is indeed art. If the pebble was intentionally engraved then I believe it is art. Only because the one who created it saw an art piece and an art piece is interpreted through the eye of the artist.
If someone, by chance, knocked over a tub of paint onto your beautifully polished structure and somehow making it the award winning master piece...would that be considered art although it was not intentional or representational? I believe it is and obviously so do the judges of the art contest. :) I believe art is whatever comes to your mind when you close your eyes. Whether that is an abstract painting of a tunnel with no end, or a miraculously detailed drawing of Nine Eleven, both are considered art in my book.