The image is a blackboard, on which a Japanese onomatopoeia called "????" in hiragana or "zaazaa" is depicted. This onomatopoeia is used in the situation when it's rainning cats and dogs. There is a good website for learning Japanese language, particularly Japanese onomatopoeia. For it, see my below comment.
Japanese onomatopoeia-zaazaa free icon was designed by yamachem for icons Png and presented to its users.
yamachem
2/5/2018