Double Happiness sign is placed for all to see as a sign of good luck.
Jewish and Chinese customs both share rituals that honor their families and ancestral heritages. The Chinese Tea Ceremony is a way for the couple to show respect and gratitude. Tea was served to both families prior to the Ketubah signing ceremony and the formal Jewish Wedding. Bride and groom both wore the most auspicious Chinese color red for the tea ceremony, changing into Western wedding dress and suit for the Jewish wedding. The color red is a sign of good luck because of its association with fire, the sun, brightness, yang life energy and the lifeblood that demons fear most.
For more information on chinese wedding traditions