This is a magic looking glass, it is a portal to the otherside. A powerful spell has been casted upon this mirror to open up the portal, so spirits can rome freely. They can hear you, they can see you, they are there to help and guide you. You can use this mirror during your spells and rituals for enhancing it's power. You can look into the looking glass and ask your spirits for answers to any question and they will find the way to answer you. This usually will happen during your dream state. You may also be able to see your entities while looking into the looking glass with your light off and a candle lite. 
 
Ask the entities for what you want and what you need they can hear you and are there to help you. 
If you wish to have only good spirits enter your looking glass please let me know so I can block others from entering. The same goes if you just want dark arts entities to come through.