What exactly is a "French work jacket"? Is it like a denim jacket?

The author also mentions "kurti shirts" and when I did a search, it seems these are the gauzy cotton tunics from India.

On her Effortless Style, Wear Two idea (pg. 20), I just can't imagine wearing two blazers, so, I'm not sure where Ines is going with this. Does she mean two different styles? Having said this, I actually did wear a denim jacket and then put my black leather cafe-racer style jacket on top, because the weather changed and I was really cold and hadn't brought a coat. It didn't look bad at all. Blazers, though?