So this does bring up an interesting point that I haven’t thought about - is it the depiction that matters, or is it the actual content that matters?

Consider the Catholic schoolgirl trope - if someone of legal age is depicted as being much younger, should that be treated in the same way as this case? This case is arguing that the depiction is what matters, instead of who is actually harmed.

Every country has different rules, standing on wikipedia.

Personally, I feel that if making completely fictitious depictions of child porn, where no one is harmed (think AI-generated, or by consenting adults depicting minors) was legal, it might actually prevent the real, harmful ones from being made, thus preventing harm.