A fifth principle of perceptual organization is that of smallness: Smaller areas tend to be seen as figures against a larger background. In Figure 7, we are more likely to see the image on the left as a black cross rather than a white cross within the circle because of this principle.
As an illustration of this Gestalt principle, it has been argued that it is easier to see Rubin’s vase when the area it occupies is smaller. The lower portion of the right image in Figure 7 offers negative image versions in case this may play a part. To avoid implicating the surroundedness principle the conventional broad borders have been removed from the four versions. The Gestalt principle of smallness would suggest that it should be easier to see the vase rather than the faces in the two versions on the left.