Lambrequins, cornices and pelmets are structured top treatments on windows often above other "soft" treatments.
Lambrequins go farther down the sides of the widow frame and can go to the floor if the window does.
There is little difference between a pelmet and cornice. They can be painted or covered in fabric.
I think this shaped cornice is charming and works nicely with the angles of the ceiling.
I am racking my brain trying to think of a room to incorporate a chinoiserie pelmet like one of these.