There's a penis hidden in this photo, but interestingly it can be detected only by those with homosexual tendencies.  Heterosexual or sexually ambivalent men see only "an empty room," "a shower door," or "a bathroom" and never detect that there is a man in the photo whose penis is visible to those with "cock eyes."  This photo is a classic example of the phenomenon that we see what we're looking for.  Our brains take in so much environmental information that we must filter out what isn't important in our lives.  Otherwise, we'd be overwhelmed.  Those who don't need cock will not even see it when it's directly in front of them.