Without going into the more minute particulars of mirrors and Feng Shui, a large mirror fulfills one requirement of a mirror: that you should be able to see all of yourself in it, not just a small part. Mirrors can make a small area look larger, or it can reflect a natural setting, bringing it into your home. A mirror hung near an entryway is believed to add the element of water to your decorating theme.
As you can see, mirrors can play many roles in your interior decoration as well as in helping you make yourself presentable for the world at large. They meet requirements that range from the very ordinary to the esoteric. Better yet, a well-appointed mirror in a beautiful frame is simply nice to have, regardless of its purpose. Whether the frame is heavy and ornate or less obtrusive, it can help keep your mirror intact. Whether you believe the old superstition about breaking a mirror and having bad luck, it is certain that good mirrors are expensive and keeping them protected with a nice frame is a good idea.