What is the author's style in On Photography by Susan Sontag?

The text is intended for an audience of photographers and consumers of photographic images. The presentation of the text as an academic monologue obviously limits readership greatly, which is unfortunate as the basic messages of the text are not intended solely for academia. The text intends to examine the history and process of photography within society and to that end it is successful. The text is markedly dated, however, by its understandable failure to anticipate digital photography in any robust way.