This is similar to a triangular hair cut with graduation. There is a previous post here post at W: Triangular with graduation formula which shows this. The difference here is that the triangular haircut at one length is done before it is graduated. This demonstration cuts the length and the graduation at the same time. In the two step haircut mentioned above there is a method for determining the angle of the triangular length. Here the angle is done by eye as the design is fit to the face. In the two step haircut the angle remains the same once the decided angle is reached. This is likely where the part first goes to the front hair line and is above the ear.
Another difference is that in the triangular haircut the length at the perimeter is truly shorter in the back. In this demonstration, the length is not shorter because the graduation extends to the perimeter.
Assess hair line, growth patterns, head shape.
Pick length and manually mold the design
Find the natural part. Comb to natural fall.
Center part in the nape and connect to the natural part
Section and cut the nape
Beneath the occipital bone take diagonal forward sections. These start at the middle part of the nape below the occipital bone. They continue to the nape hair line where they have reached about 1/2 inch to the side of the center part in the nape. The head is tipped forward
It looked like the section was pulled back straight toward the wall. It is cut so that the top part is longer than the bottom. In this demonstration it looks like the top of this section is about 1.5 inches and the bottom is about .5 inch long. The fingers are angled to follow the line of the diagonal forward part.
Further sections are taken up the center part of the nape in 1/2 inch steps. They are slightly wider than the first section at the hairline. They are pulled back and cut to the guide from the first section.
Sections are continued up with the parts working up to the back of the ear. The part has become more horizontal as it goes up the back. Sections are lifted higher in the middle of the nape than at the perimeter of the section. The guide is taken from the previous section.
On reaching the crown the sections are extended to the front hairline passing above the ear. In the back the previously cut section is the guide. Along the side the line is followed. Compensate for the ears sticking out. The hair is lifted as it is cut.
Work up the side to the natural part in sections which are also lifted slightly and cut to the previous section as a guide. The angle of the parts are all the same and parallel to the one that first passed over the ear. The hair is elevated slightly to keep some graduation at the ends . It looks like more graduation could be added to the ends by keeping the blades of the shears up and down and not perpendicular to the hair strand. This is not done in the demonstration
Head is tilted away from the cutting area. I think this is to help in turning the ends under at the end.
Do the other side the same way starting in the back.
Refine the perimeter with point cutting.
Cross check the graduation in the back.
Add product and blow dry. Use sections as in cutting and turn the ends under.
Dust the ends all over.
They cross checked this way about every which way.