Subliminal Imagery

A 1994 add for Kahlua Cafe instant coffee one can see the steam rolling above the coffee forming in image of a man and woman embracing. I imagine Adobe Illustrator w/ layers was used to enhance this photo. The designer is using "subliminal" imagery to gain the interest of the viewer. This add and more information on this type of advertising can be found in Visual Persuation-1997 by Paul Messaris.