That leaflet is an early-ish version of the surrender leaflets that would be extensively used throughout the war. I believe it's first usage was during the Aleutian Campaign. It was used in the hundreds of thousands on Kiska Island, where it was extremely effective in getting the inhabitant to surrender. Intelligence says that the only remaining Japanese thing on the island, a dog was well treated after surrendering to U.S. troops. Joking aside, the U.S. papered the island with leaflets not knowing the Japanese had left weeks before, and the bit about the dog is true, well the part about it being the only thing there, I don't know about its later treatment. I would imagine it was treated well.