I reckon the point of releasing pictures of the King, Victoria and Estelle only was to show the King, his heir and his heir's heir together. It would go a bit against the premise of the pictures, the King with his heirs, if you shove Silvia and Daniel in there as well. But I agree that a picture of Daniel and Estelle for his birthday would have been lovely.
I love the pictures. Estelle is such a cutie patootie. She looks so professional already – it's the cutest thing. The resemblance between the King, Victoria and Estelle is staggering, they look so much like each other and it's so evident when you see them together at once. I also love the fact that they included the King – we never really see much interaction between him and Estelle (I also adored the moment during Leonore's christening when the King, Madeleine and Christopher were smiling at little Estelle), it's mostly Estelle and Silvia on the maternal grandparents front, so I think these pictures were long overdue.