Woman Looking out Studio Window, the title assigned by this website, is an example of typical studio society portraiture done by the New York City Selby studio, perhaps around 1920 or slightly before. An engagement portrait? The modern American custom would emphasize the ring on the subject’s left hand. The “window”, a prop, is built within the studio itself. Lone attribution for The Misses Selby. N. Y. in graphite appears at lower right-hand corner of faux-frame print recto, printed in the middle of a larger sheet of photographic paper. The name of the subject is unknown and photograph is undated.  A short biography on the Selby sisters states:

British photographers Emily & Lillian Selby began taking photographs together while operating their first American portrait studio at 292 Fifth Avenue in New York City beginning in 1900. Collectively signing their work as The Misses Selby, the sisters, (Emily: b. 1868-1915? | Lillian: b. 1866-1964)  (1.) according to Jane C. Gover:

…were seeking an artist’s studio in New York when they happened to be offered a photographer’s studio with all its equipment. Relying on Emily’s business experience and Lillian’s degree in science, the sisters established a portrait studio and quickly became well known in Manhattan.  (2.)

1. Death dates vary for Emily. It’s believed she died “Emily Fisk”, after marriage at unknown date. Trowe’s New York City Directory lists her as late as 1915 along with sister Lily under Photographers: “The Misses Selby”. The 1916 Trowe’s directory omits her. Lily Selby died in 1964. The GenealogyBank Historical Newspaper Obituaries, 1815-2013 (United States) index shows death date of 14 October, 1964, listing her occupation as “Society Photographer”. The New York Times also has a short obit: “Selby, Miss Lily, of 1295 Shippan Ave., Stamford, Conn., on Wednesday, Oct. 14, 1964 daughter of the late John and Elisa Tuppin Selby. Funeral and interment will be held privately.”
2. The Misses Selby: in: Ambassadors of Progress, American Women Photographers in Paris, 1900-1901: edited by Bronwyn A.E. Griffith: Musée d’Art Américain Giverny, France In association with the Library of Congress, Washington, D.C.: 2001: p. 170