This is what I thought too. Without the hand they may well be typical photographs of children. With the hand they suggest that he’s reaching out to touch them which is totally random and inappropriate, especially the ones with Emilia in bed.could very well be. It also makes it easier for someone to imagine it's their hand......
I believe he adds his hand into every other photo as an excuse as to why it’s in the ones with the kids. He’ll say he does it in all photos so it’s nothing sinister.