I think knowing the context affects how one interprets the drawing. Yet it’s not only an illustration, it’s an infinitely expressive drawing, oddly sympathetic and universal. And too, in my view it does something that photographs can't do, though I can't put into words what it is.
"She wrote her final letter known as her 'Testament', to her sister-in-law Elisabeth. She expressed her love for her friends and family and begged that her children would not seek to avenge her murder."Image and quote from http://en.wikipedia.org/wiki/Marie_Antoinette
P.S., added September 17, 2006: The reason I put that quote in was because before stumbling on this (famous) drawing, all I knew about Marie Antoinette was, "Let them eat cake". The drawing however showed such an intriguing personality that I went looking up more about her. It turns out that (as no doubt everyone except me knows) she's a highly controversial figure among historians, and very likely was not as bad as she's been painted. In such cases the picture gets murkier with the passage of time until one doesn't know what to believe. But facts are facts, and her last letter was (I assume) a documented fact; and to me, her request that her children not seek revenge shows that she was not all bad.
And the Web Gallery of Art has this to say: "Marie Antoinette was only thirty-seven, but a year's imprisonment had made her look much older. Her hair was prematurely grey and, robbed of her false teeth, wig and corset and seated on a wooden plank on the back of a tumbrel, she looked a pathetic figure. After a brief loss of composure she met her end with great fortitude, dignity and calm, even apologizing to the executioner for having accidentally stepped on his foot."