From the Library of Congress WPA Poster Collection: "Poster for exhibition at the International Building, Rockefeller Center, New York City, showing stylized illustration of tree in front of cage containing a wild cat." (Image source).
New York City hosted the 1939-40 World's Fair* ("Building the World of Tomorrow") but I could not find details about the 1936-7 Parks Exhibition online. Do you have any information?
* New York's first world's fair was held in Bryant Park in 1853-54.