Bruno Loeb, to interpret the real essence of the subject he has to depict, has sometimes put him or her in some other's place by copying other artist's famous paintings.
In the vast, immense repertoire of portraits from any time or space, the secret is to find a similarity with the person you have to depict, and then, in this mysterious ambience, separated from you by centuries or years, you have also to make your portrait to continue the life of the original work.