Thanks for spurring me into looking up more about it. As a correction, while the person depicted is in fact the present Spanish king (Felipe VI), following his father's abdication, he was at the time prince.

Here is the original cover: http://2.bp.blogspot.com/-mNFvFt4lGqU/U5JJpeCCkmI/AAAAAAAAF6...

My understanding is that the cartoonists filed an appeal, which was unsuccessful: http://www.20minutos.es/noticia/375143/0/ESPANA/ELJUEVES/