The picture becomes even more fantastic when you make your eyes believe that the bottom line of the picture is the bottom line of "reality": then the light grey something (the river Thames)becomes like the glass front of a large building, on which a half-bike is fixed; an artistic graffiti-writer would have climbed half-way up to write his graffiti on a place where no-one would brush it off.
The picture becomes even more fantastic when you make your eyes believe that the bottom line of the picture is the bottom line of "reality": then the light grey something (the river Thames)becomes like the glass front of a large building, on which a half-bike is fixed; an artistic graffiti-writer would have climbed half-way up to write his graffiti on a place where no-one would brush it off.