Let’s see how to draft the pattern of this asymmetrical dress.
Start from the basic block of a dress with darts and full front.
On front and back, flare from the side seam 5cm and redraw the armhole a couple of cm inwards on the shoulder.
Erase the waist darts.
On front only, cut in the center and draw the slash lines for manipulating the shoulder darts.
Get the right front, cut through the slash lines and close the shoulder dart.
Open the volume for the drape and draw an extension for the bow.
Redraw the right front with the additional volume.
Manipulate the dart on left front to have it in the side seam, and this is the finished pattern: back, left and right front, additional piece for the bow.