Any molecule has a mirror image.
Some molecules are congruent to their mirror images- if the reflection is rotated 180 degrees it matches the original. An example of a molecule with a congruent mirror image is 2-propanol. In the following diagram the blue atom represents the middle of the three carbons, the yellow are CH 3 groups, the red is oxygen and the white are hydrogens. The mirror image of the 2-propanol molecule is shown opposite it. When the mirror image is rotated 180 degrees, it is apparent that it is in fact the same molecule as the original.