Every year Rockeferller Square becomes the Christmas heart of New York City, with the ice rink opened inside the frame of flags from all the states, and with the famous huge Christmas tree soon to be flown in by helicopter. People from around the world snatch selfies and little bits of joy. This year, workmen are building a tiny hamlet row of identical structures from scratch, to fill in the holiday vision, by adding a little bit of new to an old celebration.