It’s a very useful occupation, especially for preschoolers, as it helps to develop spatial thinking, attentiveness, accuracy, diligence, fine motor skills, space orientation skills.
You can do these tasks both in pair with your kid, and in a big company. First draw the task on the sheet of paper, set the start point. Then start to dictate the direction and the amount of the cellules. E.g. one cellule to the right, one cellule down etc. till the line closes.
It’s highly important to explain the terms “left” and “right” to the child. You can even give him or her some hints on the paper.