How dreadful.
Sadly this out of tune, badly produced singing (I'm talking about the teacher) and the mistaken belief that solfège exercises (such as singing in sixths) will help build the vocal technique are horribly prevalent in France.
Clearly no attention has been paid to core stability, jaw tension, tongue placement, using less air etc.
The best that poor student can hope for is to end up with the same screeching mess of a voice that the teacher has.
Still, we're good at wine, cheese and chocolate!