I built a similar device in the seventies. It had the row of lights on a stationary board, and you have to move your eyes across it to see that it says 'shit'. It was called 'Grafitto In The Eye of the Beholder', and was quite difficult to build because memory chips were not part of my repertoire at the time. I built Justtosee with enough memory to print a thousand words, never thinking that I would have nothing for it to say. While I was making it, my son asked me what I was doing with the fishing rod. I told him the whole plan. He asked, "Why?".