...because people have too much time on their hands. Aside from the alleged "SEX" subliminal message, there has been a rumor going on for years that the 2002 IMAX poster of The Lion King in which the lion's face (reused from the original 1994 film poster) contains a subliminal message of the back of a woman wearing a bikini.
*Sourced from The Visual Community Guy
I know it's silly and unintentional of the poster artists, but share your thoughts.