Immediately after the chupah, the bride and groom adjourn to the "yichud (seclusion) room," where they spend a few minutes alone. The couple is traditionally escorted into the room by their parents. After a few moments, the in-laws slip out, leaving the couple alone. The door is then locked from the inside. The couple remains secluded in the room for at least eight minutes.
The chupah witnesses must ascertain that there is no one in the room besides the bride and groom, and observe the door being shut and locked. They then wait outside the room for the aforementioned amount of time.
Once inside the room, the couple breaks their wedding day fast. It is also a time when the bride and groom customarily exchange gifts. Many grooms use this time to present the bride with a diamond ring. The bride also dons all the jewelry which she removed before the chupah.
After all the public pomp and ceremony, it is time for the bride and groom to share some private momentsChabad custom is to place a sterling silver spoon on the threshold of the yichud room before the bride and groom arrive. The groom and then the bride step over it, right foot first, into the room.
At Sephardic weddings, the newlywed couple customarily waits until after the wedding reception before entering the yichud room, and witnesses are not asked to observe the couple's entry into the room.
Jewish marriage is comprised of two stages, kiddushin (betrothal) and nisu'in (marriage). There are certain halachic authorities who maintain that the final stage of nisu'in is not finalized until the groom takes his bride to a secluded area where they spend some personal time together. Jewish law forbids a man and woman who are not married to each other from being secluded together. Thus entering the yichud room together is an act which symbolized their newly married state.
After all the public pomp and ceremony, it is time for the bride and groom to share some private moments; the purpose of the entire ceremony! Even while surrounded by a crowd clamoring to shower them with love and attention, they must take a break to be there for each other. This is an important lesson for marriage -- the couple should never allow the hustle and bustle of life to completely engulf them; they must always find private time for each other.