He does not care that it is from pixabay or that you are allowed to use the image. He is hitting hundreds, soon thousands with his damn bot, trying to embarrass posters, making it look to others like you cheated or stole the image. I would suggest, if he does it again, just flag his post.
We must all do the same until he is below zero in rep.
hello mr. arthur.grafo
i edit that pic - now it ok