Interesting pictures. In the lower one the Duchess of Gloucester appears to be giving Kate a disapproving look, Michael of Kent is aiming a similar look at Wills, Zara and Autumn seem to be passing comment on someone or something across the aisle and Eugenie is clocking the sleepyhead. She has also kicked her shoes off! Harry is in a world of his own.
Maybe, the older Duchesses disapprove of the younger ones turning around in their seats and/or chatting to those behind or in front ... although perfectly normal behavior for the rest of us, it might be considered a little déclassé at a Westminster Abbey service with royalty.
Or, it could just be normal, everyday sourpuss expressions! http://royaldish.com/Smileys/royaldish/nono.gif