Here is the story behind this discovery.
It seems wonderful to see the face of a man whom I regard as a real prophet. This image is far more impressive than the portraits done at the time. It now seems a little easier to imagine how he did what he did, and why so many felt inspired to believe and follow him.
NOTE ADDED: Here are a selection of first hand, contemporary descriptions of Joseph Smith. There is a fair bit of variation; but observers seem to converge on the fact that he was unusually tall, had blue eyes, a fair complexion, large nose, light brown hair, and an athletic physique.