Australia's constitution does not contain an express freedom of speech, and the courts there have apparently recognize a much narrower right to political speech than is enforce in the United States. Here in the United States, the Supreme Court has previously held unconstitutional the application of child pornography laws to "virtual" depictions of minors.
The NSW judge relied in part on a rationale the U.S. high court expressly rejected: that cartoon depictions of children help perpetuate a market for actual child pornograhy. He also suggested that this holding was necessary to prevent the harmful use of drawings, etc. to depict actual, individual minors engaged in sex.
The judge held that whether a drawing or other representation of a minor falls within the law depends on the facts of the case, and in particular the degree to which the depiction is clearly meant to represent a human child or teenager:
Bestselling fantasy author Neil Gaiman says the ruling is "nonsensical in every way that it could possibly be nonsensical," and has some choice words to say about the harmful implications of such a view of the law - including that Australians could now conceivably be locked up for owning his longtime friend Alan Moore & Melinda Gebbie's acclaimed book Lost Girls. Gaiman suggests this is a good occasion to contribute to the Comic Book Legal Defense Fund.
Merely to give human characteristics to, say, a rabbit, a duck or a flower, to use some other familiar images, would not suffice if it were fair to say that the subject of the depiction remained a rabbit, a duck or a flower. A stick figure could not, I think, depict a person.... No bright line of inclusion or exclusion can be sensibly described. ...Accordingly, if it were reasonably possible that the depiction is not that of a person, the offence is not proved. It follows that a fictional cartoon character, even one which departs from recognizable human forms in some significant respects [as the Simpsons characters do], may nevertheless be the depiction of a person within the meaning of the Act.