Bread Making of Chief Crumb and A Little Bird Crust
Coupe means "cut" in French.
Making some even and shallow cuts on the top of the loaf will release the air pressure inside the dough, and helps shape the bread when it rises in the oven. You can use a baker’s blade, knife, or scissors.
Well, it seems like Chef Crumb is making leaf- shaped cuts on top of the loaf.