Have you seen this advertisement for the movie "The Grudge 2"? Centered in a pale, bloodless face is a wide, frightened eye. Scary enough to provoke nightmares in adults!
My son saw this billboard as we drove in the car. He pointed it out to me... "Look mom! The number 2 picture!"
"Yes, it is a number 2 picture!" I replied, much relieved that was all he saw.
Just a quick example of that old expression "in the eye of the beholder".