The interface has a character (in this case Elmo, but can be changed as the child wishes). The character has his mouth open with teeth visible.
As the child grabs the brush and starts brushing her teeth, her hand’s motion is replicated by a brush in Elmo’s mouth.
The child can see Elmo’s teeth getting cleaner as she brushes.
Once all teeth are white, brushing concludes.
After brushing is done, Elmo says thankyou and goodnight (cuing the child to sleep).