It is also different media.
Found this on an art website:
A good place to begin thinking about Alma Thomas’s ravishing late work might be the moment in 1964 when, close to paralysis and bedridden, the 73-year-old artist found herself staring at the hollyhock shadows she had known her entire life and calculating how to use them in her paintings. A year earlier, she had seen the late Matisse cutouts at the Museum of Modern Art in New York. Matisse’s work had prompted her to paint an acrylic-on-canvas version of his collage The Snail (1953), in which nearly all the original colors were reversed. Thomas named her painting Watusi (Hard Edge), after Chubby Checker’s dance hit “The Watusi.”