And I disagree. There have been many pictures of people covering their chest with foreign objects, such as hands or their hair. That's even an older concept than kissing yourself.

Janet Jackson did both. Someone else's hands were covering her chest on the cover of Rolling Stone. And in the video for "Together Again" she was seen holding herself provocatively. Oh and for the video for "All is Full of Love", it was a male and female robot that were on top of eachother.

And while we're on the topic of copying people's ideas, remember the infamous "Dune" ad? That ad came out before "UNITE!" was released, and the picture from the cover totally ripped that picture off. There are rarely ever original concepts for album covers.