Reflections can be seen as an interesting feature that can serve as an add-on element to give additional meaning and add drama to an image.
In some occasions reflective surfaces of the actual surroundings can produce surreal images.
At times having instances of the same subject that exist in two visual environments my seem like some kind of a portal to a parallel world viewed through one combined frame.
This is especially visible with different lightning conditions or when additional elements like clouds, rain or snow are introduced that help produce a certain level of surrealist feeling.
Also partial reflections, where only a part of the reflection is visible, can provided interesting grounds to further enhance visual experiments and the general mood of the photograph.