I think it's a trick from the creepy guy.
He want to freak her out just as the time when he went to his room and she thought that he was a gost.
Hope she will come back when she was 5 again.
So that is why when she looks in his green eyes she fells pain, I feel sad for the original vonny, bit the grand Duke seems like he has some secrets of his, looking fow3to read the rest.