- "As they entered Lockhart's darkened office there was a flurry of movement across the walls; Harry saw several of the Lockharts in the pictures dodging out of sight, their hair in rollers."
A roller is a cylindrical object that can be rolled into a person's hair in order to make it curly or wavy.
Petunia Dursley owned some rollers, and wore them while she slept. Gilderoy Lockhart, despite having naturally wavy hair, also used rollers. A stray roller of his was left behind on his office at Hogwarts School of Witchcraft and Wizardry.