O. Henry's "The Last Leaf" is about the importance of having fierce energy on your side to battle the fierce forces of nature and how art, when it addresses what is vital in the gap between us the world around us, offers us a connection to life.
O. Henry may also be offering his take on the battle of the sexes, with the short, bearded, unkempt artist, unable to care for himself or to create much art, possesses the fierce male energy that the lesbian lovers living above him lack. Sue, the tougher of the two, talks to Joanna in a manner a mother trying to lift the spirits of a sick child. The cutesy nicknames, Sudie and Johnsy, reflect a distracted way of talking to one another that never seems real. Though men may be difficult to live with, love is not the romance pictured in magazines with all the rough edges smoothed over. Love is not so much about primary relationships as it is about reaching beyond oneself to touch another. Art, as it turns out, is much the same.
Behrman paints his masterpiece once his love of life directs him to the subject his audience needs to see to hold onto hope and hold onto life. Art does not need a canvas. But it may need to stand apart from the artist to be seen. And, when it is discovered as art, the true nature of the artist is discovered, as well.