The Royal Collection’s notes specify this is an oil painting so this is presumably a black and white photo of it.
From pinterest.com/andrewschroeder/1810s-art/; enlarged by half.
Princess Charlotte is shown all dressed up with some place to go in an Empire-waist dress and feather ed hat.
Keywords: 1817, Chalon, Princess Charlotte of Wales, Welf family, Wettin family, Princess, British, curly coiffure, feathered hat, square neckline, modesty piece, Empire waistline, close skirt, shoes, coat, long tight sleeves, fur cuffs, fur, gloves, shoes, handkerchief