What purpose do the little arrows with boxes that say "wooden hanger" and "new trench coat" serve

In chapter 3, Vladek had gotten angry at Mala for using a cheap hanger instead of a wooden hanger for Art's coat. Vladek had thrown out Art's coat replacing it with his old windbreaker. In chapter 4 we see Mala hanging Art's new trench coat on a wooden hanger. Art is trying to rebel against his father any way he can.