All the space behind the mirror will become dark, and all the space in front of the mirror will acquire an exalted illumination.
If a mirror is mounted on a truly adjusted polar axis, the plane of the mirror being parallel to that axis, the normal to that mirror will always be directed to some point on the celestial equator through whatever angle the axis is turned.
Standing in front of a full-length mirror will also help to keep you reasonably presentable.
If you're considering a frameless mirror for the bathroom in your home, make sure to consider what type of mirror will work best in the space.
In fact, many of the designs you'll come across when shopping for a Mission mirror will refer to various elements as being in the "Stickley tradition."