The exaggarated appearance he photoshops on these kids is to objectify them, make them more sexualized (what he is apparently sexually interested in - their mouths) and "ideal" but also distinctively less human at the same time. He also makes them all look more or less the same, stripping away what makes them individuals. Dehumanized and having their individuality stripped away, just like a doll then, they only exist for his pleasure. Dolls also need to be played with, they don't have agency and don't act by themselves, which is probably something he would not like because he wants to feel in control. That he likes to play these characters online shows that too. That he does the same to himself might be a kind of regression, might also be an interest in being in that vulnerable role, as a turn on. He might also actually identify with what he wants to do to these children, on some level, maybe because it happened to him, or it might to be an attempt to normalize it to his own mind, by putting himself on the same level, even if obviously just superficially. Or maybe it's just a byproduct of the obviously quite elaborate roleplay and stories he comes up with in his head. He's not only sexually interested in children, but in a specific version of children he came up with in his mind. I don't think he's stupid or clumsy at play-pretend to be a child, I think that is exactly what he wants them to be. Of course it's all just speculative. I could imagine this guy to be potentially dangerous. It's not good that he got a reality check and goes into hiding. It will make him more careful.