Video prompt: a drawing of a beautiful blue butterfly, created by an artist using a marker and pen. It is a simple yet captivating piece of artwork that showcases a delicate and vibrant creature. The video is a great example of an artist's creativity, skill, patience, and passion for their work.
Defect: Deformation (any reason involved with a movement)
Explanation: The brush's movement trajectory and the pattern it forms show slight distortion, and the movement appears unnatural.