Rangiri (乱切り) is when you rotate and cut the vegetable.
From the end of long rounded vegetables such as carrot, cucumber, gobo, cut diagonally while rotating the vegetable a quarter between cuts. This not only makes an attractive shape that is good for stews and simmered dishes but also gives bigger surface space to absorb seasonings faster.
You can see this technique in this video.
Watch Japanese Cutting Techniques 野菜の切り方
The Japanese have specific names for Japanese Cutting Techniques. Cutting the vegetables a certain way accentuate their look, flavor, and texture.