First and second grade artists learned about Positive and Negative Space. Although I hope the Art Room is always a "Positive Space," sometimes is is the use negative space in a piece of art that makes it interesting.
Negative space, in art, is the
space around and between the subject(s) of an image.
Negative space may be most evident when the
space around a subject, not the subject itself, forms an interesting
or artistically relevant shape, and such
space occasionally is used to artistic effect as the "real" subject of an image. from
Wikipedia
Click here for some examples of art with a creative use of Negative Space
