Originally, police said they thought Domonic Gaines, 22, of Colerain was holding a handgun in the photograph but it later turned out to be a BB gun, WXIX-TV, Cincinnati, reported.
Police said the close proximity of the gun to the child created a substantial risk of physical harm.
Gaines was arraigned on child endangerment charges. He was being held without bond in the Hamilton County jail.
Gaines' father, Wilson Dykes, said the matter had "really been blown out of proportion."