fingerprints on glass

My thinking today at lunch ...
You fill up the cylindrical glass with water. You take it to hands and you can see fingerprints through the water. The others parts of glass is like mirror. Why you see only fingerprints and nothing else? Can you see similar phenomenon if you use something different on glass? And why is that? What's happens after emptying the glass or fill on with different liquid and why?

Sorry for my bad English and thanks for your answers.