The photograph very clearly shows the Earl (eldest son of HRH The Princess (Victoria) Mary, Princess Royal and Dowager Countess of Harewood) holding the Coronet of a Grandchild through the female line and his wife holding the smaller female version of a Coronet, but that of an ‘ordinary’ countess.
The Earl was the senior grandson of a Sovereign through the female line present as the Marquis of Carisbrooke was too ill to attend in 1953. However, in claiming that a smaller version of this Coronet didn’t apparently exist, I forgot, of course, that the Marchioness of Carisbrooke WAS there and would lay claim to the smaller Coronet over the younger Countess of Harewood.
I am indebted to Gustavo for that information.
Talking of Grandchildren of a sovereign through the female line, I will soon be posting a blog entry about the Earls of Snowdon.