I get what you are saying, but at that time I'm not sure that that is fair. After a abdication, a war, and a marriage, the royal family was anything but dull. And Cecil Beaton was a real favorite of the Queen Mother for his rejuvenation of the monarchy with his totally different pictures of the then Queen Elizabeth. Cecil Beaton certainly could never be called dull.
Prince Phillip didn't really like him, remarking on his floppy hats. The Queen Mother liked him. She had a propensity to gays in her entourage. I expect he got the job of photographing the baby pictures of Charles because of the Queen Mother.
Personally I like Richard Speaight"s images of the Queen then Duchess of York and Elizabeth the second of the Vanity Fair images