The little brass birdie being held by the young child was a popular photographer's prop at the time period, and most were made in Nagatuck, Connecticut. The little "well" at the bottom held a small amount of water; and squeezing the rubber bulb sent a variable amount of air through the water, and up to the birdie's movable mouth, making it "warble." If the sound didn't capture the child's attention, I guess the photographer had to relinquish the entire bird.