At the risk of sounding facetious, the quick and easy answer is :autism:.
However, it goes well beyond that. Bryce isn't just autistic; he has turbo-charged, weapons-grade autism. Then, on top of that, he has all these bizarre fetishes and/or some really twisted idea of sexualism that bleeds over into his work. And, for the cherry on top, his parental units don't seem to exert any sort of control over him (or, possibly, are just tired of him constantly chimping out) and apparently don't know or don't care that he posts borderline pedophilic content on Deviant Art.