The Black Door

Having passed this door many times on my walks up Bermondsey Street in SE London I have always wondered if there was an image hidden in the black door. Took a shot today in mono and it looks as though there is an illustration hiding away.

I am convinced it is a graphic of the Thames river bank. My wife is not so sure. Looks as thorough I will need to take some more photos in different lights to see if I can get a more detailed image.