No I doubt that. It sounds more like to me he likes more interaction and solicitation with his sexual desires. If she looked like an adult, then there's lots of legal adults he could be pursuing for solicitation of intimate lewdities... and pornography of them as well.
What's bizarre about it being illegal to be involved in the distribution of pornographic pictures and videos of sixteen and seventeen year olds though even if you can fuck them? They're still not adults in most legal senses of the words even if you can fuck them sexually.
I get that it's not perfectly consistent, but child pornography of sixteen or seventeen year olds as opposed to eighteen and over does strike me as something that seems fine to me legally and I'm not sure why, beyond "bizarre" numbers why it should even be considered bizarre to make child pornography of sixteen and seventeen year olds (and under obviously) illegal even if the age of actual consent to sex is different. Having pornographic pictures of sixteen and seventeen year olds seems skeevy and should be illegal IMHO even if the age of consent is lower.
Obviously sex can have a lot of potential pitfalls, dangers and vices and whatnot coming out of it, but so can pornography and furthermore it can be distributed and spread that sort of degeneracy about.
Sixteen or eighteen or twenty one for various adult things might seem arbitrary, but that's just the way it is. If there's going to be a benchmark for all of these things, you have to pick an age since not everyone matures at the same age (or enough at all to engage in adult things lol).
Just IMHO it doesn't strike me as bizarre at all if I think about it a little longer.