Claire Foy, you may have noticed, is our new favourite celebrity. We have grown fond of her, not least because of her sympathetic portrayal of the Queen in The Crown, and it cheers us up to see a picture of her, if not in character, with crown and ermine stole, then just out and about with... a new haircut. Ah. This haircut, which must surely be for a part - Joan of Arc, Jack in Lord of the Flies? - is one of those that reminds you just how serious a short haircut is. Claire Foy, who has hitherto always looked sweetish and pretty (even in new film Unsane), looks neither with this savage short-back-and-sides, and that's the way it goes for most of us who attempt short hair. You don't realise the...