Cecilia Gallerani was about sixteen when Leonardo painted her at the Milan court, where she was the mistress of Duke Ludovico Sforza. The ermine may be a pun on her name (galê is Greek for weasel) and an emblem of the duke.

Look at the hand stroking the ermine, long and elegant, with every knuckle and tendon carefully observed. The black background was added later by another hand.