Many Shuls decorate their Batei Midrashim with flowers, trees, each according to their own Minhagim. But this is spectacular – watch as Mispalilim in the Breuer’s Shul (KAJ) located in Washington Heights, NY, decorate their Bais Medrash for Shavuos. The tedious job starts 48 hours before Yom Tov starts.