Good question.
As far as I'm concerned there is little to no difference concerning the subject of the desire, everyone likes something different. But, same goes for heterosexuals. They also have an object to their desire, one that is considered 'normal' and therefore more acceptable to pursue than any other interest to a greater majority of people.
But that's why I see the issue of drawings of child porn as I do. While I feel it is also a freedom of speech issue, more importantly I feel it could be a more positive outlet for a pedophile. It's like how some losers I know could very easily go their entire lives without sex so long as their pile of pornography is large enough... Saves some poor women from suffering. :lol: