French artist Albert Sauteur suggested in 2014 that differences between the paintings were accounted for not only by the model having aged, but that the narrower face and closer eyes in the Louvre painting could be accounted for by Leonardo experimenting with painting from a binocular visual perspective, rather than the traditional monocular perspective. British fine arts consultant Archibald Cecil Chappelow of the Royal Society of Arts, wrote in 1956 that "the face is superbly painted, and the hands more neatly defined than those in the Louvre painting". Asmus specifically asserted that "portions of the hands in the Louvre painting have been criticized as being 'fat and ugly'", while "it is intriguing to note that the Isleworth thumb is more slender and closer to what would be expected from Leonardo". Asmus notes that this may be the result of inept repair work later on. Konody further stated of the painting that "hands, with their careful and somewhat hard drawing and terra cotta coloring, suggest at once the name of Leonardo's pupil, Marco d' Oggionno; whereas the inimitably soft and lovely painting of the head and bust, the exquisite subtlety of the expression, the golden glow of the general coloring, can be due only to Leonardo". Spiridon thought that "[the redness of the hands is probably due to a bad varnish that could be removed". Konody found the features of the Isleworth painting overall to be "more delicate" than those of the Louvre painting, stating of them, "let it be boldly stated, far more pleasing and beautiful than in the Louvre version".