Pictures are not merely imitations of visual forms, nor are they merely signs that signify or stand for things of the kind they represent. Pictures, like hobby horses, are props in games of make-believe in which people participate visually, and also psychologically.
Walton, Kendall L.
"Make-Believe and Its Role in Pictorial Representation and the Acquisition of Knowledge,"
Philosophic Exchange: Vol. 23
, Article 1.
Available at: http://digitalcommons.brockport.edu/phil_ex/vol23/iss1/1