Board Thread:Spoilers!/@comment-25562474-20141022015430/@comment-24674051-20141024131328

Going back to the original story for the Snow Queen, the Mirror that the Demon had made had the ability to make people only see the bad attributes in others. when the mirror fell and was shattered, parts of it went everywhere. If a piece got into a persons eye, they were affected by not being able to see the good qualities in others. and if a piece were to ever get to a persons heart... well....

This may be the episode where we see the effects of smashing the mirror.