Camilla, Duchess of Cornwall is rapidly becoming our favourite royal in terms of faces pulled at photo opportunities.
Backstory: Charles and Camilla are on a thorough tour of Cornwall and the Scilly Isles to celebrate 60 years of Charles being Duck - sorry, DUKE - of the area. As such no photogenic animals, small children, crafting tables and foodstuffs are safe.
This particular trip involved a 12 year old duck (called Jemima Puddleduck) being introduced to the Duchess. We can only assume she's a republican (the duck not Camilla).
Here are some more royals (mostly not pulling faces)