This postcard, published by The Rotograph Company in New York City, has no date or postmark. According to a website devoted to the history of The Rotograph Company, it actively produced postcards only from 1904 to 1908. The postcard has a divided back. U.S. postal laws did not allow divided back postcards until 1907. Thus, this postcard was likely to have been produced in either 1907 or 1908.
Note the woman in a long dress on the beach with children. Also notable is the scrubbiness of the brush covering the Headlands and the sparsity of cottages.