Three lion cubs are lying down on what appears to be a wooden floor and looking to the right of the camera. Two have their mouths open. According to the script at the bottom right in white, these animals were at the San Diego Zoo in Balboa Park, San Diego, California. This is a Real Photo postcard (RPPC) made with Azo photo paper (as evidenced in the stampbox on the back of this card). The Real Photo process allowed photographers to take a "snapshot" and have it finished at a photo shop that printed it out on postcard backing for mailing. This type of Azo papers was made from 1917-1930.
