The Rabbi's Hat

This picture from the Girona Jewish Museum apparently depicts a Jewish wedding. The rabbi is wearing a bishop's mitre. Did rabbis ever wear such headgear? If not, how come this picture? Was it done by a non-Jew who thought that's what clerics wear? What seem to be crosses on the hat makes that seem more likely. In which case, how did the picture happen?

I have something of an interest in the story of Jewish hats (we didn't always keep our heads covered, not before the 14th century) and am also intrigued by ecclesiastical headgear. So I'd really like to know the answer to this.