A tinted mirror which has been treated to reflect a modified image of skin is used to allow a subject to consider a potential change of the appearance of his/her skin, which would follow from the application of a cosmetic product such as self-tanning product. The mirror may be tinted with a brown hue so as to reflect an image that corresponds to the change of coloration of skin after the application of a self-tanning product. The invention may be used in beauty parlor or supermarket aisle to help a subject visualize the potential effect of a self-tanning product on his/her skin.