There are no copyright markings pertaining to the image as can be seen in the links above. At bottom of the uncropped poster is made in USA, Morgan Litho Co. Cleveland, O.--they printed the poster--some numbers which appear to pertain to the print job for the poster.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.
{{Information |Description=Poster for the 1933 film ''The Whispering Shadow''. |Source=[http://cartelesmix.es/images/CartelesW/whisperingshadow33001.jpg source] |Date=[http://www.imdb.com/title/tt0024768/ 1933] |Author=Mascot Films |Permission=Pre-1978...