From pinterest.com/katmaxoz/russian-court-dress/.
Here is Elizabeth Alexeievna’s coronation dress seen in the last image seen from the side, probably with panniers added.
Keywords: 1801, Elizabeth Alexeievna, Luise Marie Auguste, Prinzessin von Baden, Елизавета Алексеевна, Princess, Tsaritsa, Baden family, Romanov family, Russian, lace-edged modesty piece, shallow U-neckline, under-dress, fitted bodice, lace bertha, scoop neckline, over-dress, long sleeves, lace ruffles, waist sash, close over-skirt, train, under-skirt, panniers, coronation dress