Why did this little exercise help her students feel better about themselves?

Question

As the school year was progressing, a teacher was distressed that more and more of her students were beginning to tease and make fun of one another. She decided to do something about it. When they returned to the classroom after Spring Break, they saw a mirror on the wall with a sign next to it.
When one of the students came to her crying about the names she had been called at recess, she sent the girl to the mirror with these directions: Read that sign quietly to yourself. Repeat it over and over, gradually running the sounds together. Each time, look at yourself in the mirror. Soon you will be smiling.
Sure enough, when the student followed these directions, she came away smiling.
Each time a student would come to the teacher feeling low, she would give them the same directions. Sometimes they would have difficulty, so she would go over to read the sign with them. Eventually, each one would come away smiling.
This is what the sign said: I.Y.Q.Y.Q.R.

Why did this little exercise help her students feel better about themselves?