Moire

In physics, a moiré pattern is an interference pattern created, for example, when two grids are overlaid at an angle, or when they have slightly different mesh ...

and the man with the cane - all together caught me. Took dozens of people there in same spot, but when I saw him with the cane I was happy. Why? Who knows.

Joel Meyerwitz a street photographer says that we "all have our inner casting director. This one here you don't care about. This one has dignity, tragedy, bearing. Something speaks to us". I think it must be true.

More detail in large of the patterns.