The pixie dust effects in this sequence were hand-painted on animation cels by effects animator George Rowley; unlike typical water or rain particles, the dust was designed to fall slower, starting from an apex point, gradually becoming matte in texture, and "popping" as it descended to create a whimsical, fairy-associated sparkle...a technique Rowley adapted from his concurrent development work on Tinker Bell's magic for Peter Pan (released later in 1953).
According to animator Marc Davis, this was Walt Disney's favourite piece of animation