The solemn penitential prayers called selichot start each year before Rosh Hashana on a Saturday night. This year, that Saturday night fell on September 5. Here is video of how these penitential prayers were conducted in the main synagogue in the international headquarters of Chabad-Lubavitch located at 770 Eastern Parkway in Brooklyn, New York.
The late rebbe of Chabad-Lubavitch, Menachem Mendel Schneerson, died in 1994. The yellow pins, flags and banners you see in the video proclaim Schneerson to be the messiah, as do many of the slogans written on yarmulkes. One of the songs sung repeatedly by hasidim in the video proclaim Schneerson to be the messiah, as well. Schneerson's chair is left empty at the front of the synagogue, and an aisle (shvil) is formed by hasidim to allow the rebbe to 'walk' through the crowd to his seat. Many of the hasidim also appear to be drunk and if you look carefully, you'll see a number of them pray toward Schneerson's empty chair, not the ark containing the synagogue's Torah scrolls: