The Prophet's Wives Have to Cover Their Faces

The word Jillab itself is something that you said goes on the top and then covers the entire body like this. Is it mean that if you're wearing a Jillab by default, you're definitely covering your face or not? The woman can be without it. It could happen that she put her off because she's not going to do anything. So in the eye itself, because obviously it doesn't mention face in the eye, it says Ale Hina, all of them.