Optical Illusion
This blog is usually pretty graphic and visually oriented, but I don't know if this will work for you or not, but I will try. I was in this new hallway in Rockville Hosp., where Martha's Mother had some therapy. Here is a pic of the hallway, and at the time of the optical illusion, I was down at the other end looking this way.
Well, the hospital wing is under construction, and I looked out the window to my right and saw what I thought was a plastic-wrapped pallet of chairs out there, waiting to be used.
But I realized it was a plastic pallet, precicely superimposed by the image of chairs inside to my left behind me in the hall. Maybe you had to be there.