are you sure? I've just seen three of him with Pia walking, in one he had a mobile phone in his hand, in the second you can't see his hands and in the third there was nothing in his hand :ermm:
that's a part of a picture, where she leans on her mother, isn't it?
here's something else:
Cour grand-ducale de Luxembourg - La Princesse Alexandra a visité le festival Traffo