It looks to me that at one point after he has created a slight teardrop shape he presses down firmly on the bottom narrow end of the uncooked nan to lightly stick it to the workbench so that while he coats it in oil/water? it will retain that shape. By pressing on it to lightly stick it to the table he ensures that it will not shrink back into a round shape.
I have made enough bread and pastry to recognise this technique.
If your book delivers the goods I will still pay you for it.