by yamachem - uploaded on July 6, 2015, 3:40 am
The image is a blackboard, on which a Japanese onomatopoeia called "きらきら" in hiragana or "kirakira" is depicted.
This onomatopoeia is used in the situation when the stars or jewels are shining brilliantly.
There is a good website for learning Japanese language, particularly Japanese onomatopoeia.
For it, see my below comment.