For 70 years, the Queen combined, with great success, two roles: head of state and head of the nation. These roles are both complementary and contradictory.
As head of the nation, the Queen sought to represent the country to itself, and indeed came closer than any monarch in history to reaching the soul of the British people. A head of the nation has to represent the whole nation, not just one part of it, and that requires political impartiality.