Despite being a pillow, Roselinen has a human-like appearance. She has peach-colored skin, a round face, waist-length blonde hair, and black dots for eyes. She wears an orange, floral dress for most of her appearance (unlike Jay or Bonnie). She has large lips but a small mouth, and is slightly shorter than Finn. When she and Finn are married, Roselinen wears her blonde hair in a bun with two strands framing her face. In her middle-age, her features are paler and her hair is now in two ponytails, framing her face. When Finn is on his deathbed, Roselinen's hair is white, and she wears a red dress with light-orange ropes around her collar and sleeves. Her face is now even paler and has more wrinkles.