The function of the first mirror is to look at the second mirror, and the second mirror looks at the ponytail, so that you can completely cut off the ponytail.
Comb a few strands from the right (left) side of the face, cut them to a suitable length, and then comb a few strands from the other side of the hair. Then pull the cut and uncut to the chin and cut off the irregular ones. After the front hair is cut, the back hair is more convenient. However, you'd better find someone to help you cut the back hair, which may be uneven.