Using mirrors, you can more than double the apparent size of the room without adding any actual space. Mirrors reflect, but to give the illusion of more space, you need to extend the mirrored surface all the way to the adjacent perpendicular wall or ceiling surface — or both. If the mirror is used more as an object hung on a wall, the effect is different. It can still add character but may not make the room feel larger. When a bath is fairly spacious or has a period feel, then this more limited use of mirror is quite appropriate.
Adapted with permission from Not So Big Remodeling, by Sarah Susanka and Marc Vassalo, published by The Taunton Press (2009).