In this image, there is a short depth of field with the woman being portrayed sharply in comparison to her background. This contributes to the composition by the sharpness bringing attention to the woman instead of everything else around her. This picture was taken in Washington Square, a very busy destination or location, yet the business of this location would not be something you would know in this picture because of the short depth of field used by the photographer. Instead, the image shows and focuses on the woman, who is sitting peacefully with the necklace, which is the opposite of her surroundings.
Good description of depth of field.