In both versions of this very classically-inspired painting, the Empress nonetheless wears her ermine-lined cloth-of-gold Imperial mantle, and the bodice of her "antique" gown is crossed by the sash of the newly created Order of St. Vladimir. (In the later version, the badge of the order is visible, pendant from the sash, and she also wears the order's collar, while the star is embroidered on her gown.) Each painting is rather an extravaganza of allegory and commemoration - the sculpture of Justice; the eagle crouched on a stack of books, an olive branch in his beak; poppies burning in the brazier; the ships at sea - but the second version exemplifies a much more "proper", i.e., drier Neoclassicism. The second also illustrates a particular whim of the aging Empress: she was often unhappy with the way she was portrayed in her later portraits; viewing her 1778 state portrait by Alexander Roslin, she complained that he had given her "a face as common as a Swedish pastry cook's". So, when new portraits were being copied, she often gave instructions that the artist and/or his studio substitute, as a model for the head, her favorite portrait by the artist Feodor Rokotov, which she felt made her look younger and more attractive.
(I haven't found the first painting attributed to anyone other than Levitsky, but I have to say that in many ways it looks more like the work of another of the Empress' favored artists, Lampi the Elder. But Lampi only arrived in Russia in 1791; could the first painting be later rather than earlier, and by a different hand? At any rate, the two paintings, so similar in composition and content, are very different stylistically.)