1. An image displaying medium on which a composite image is displayed, comprising: an image displaying medium; and a composite image displayed on the image displaying medium, wherein the composite image includes a displaying image composed of mesh points having a first linearity and a latent image composed of mesh points having a second linearity, the latent image being embedded in the displaying image on the image displaying medium; and wherein, when the first linearity and the second linearity are enlarged by an optical system, the mesh points having the first linearity generate a first moire pattern and the mesh points of the second linearity generate a second moire pattern, the second moire pattern being different from the first moire pattern.