The ornamental design for a mirror, as shown and described.
FIG. 1 is a front corner perspective view of a mirror according to an embodiment of the invention. The view from the adjacent front corner being a mirror image thereof.
FIG. 2 is a front elevational view of a mirror according to an embodiment of the invention.
FIG. 3 is a side elevational view of a mirror according to an embodiment of the invention. The view from the opposite side being a mirror image thereof; and,
FIG. 4 is a top plan view of a mirror according to an embodiment of the invention.
The backside of the mirror is not shown and forms no part of the claimed invention.