The dwarfs are cartoony characters. Compared to all the other human characters that populate the film, they were reportedly more fun to animate because they did not require absolute likeness to human movements. That said, they were frequently around Snow White or the Prince which meant that they needed to move relatively realistically and to be believable characters.
Rotoscope was also used in some sequences, notably the dance party, and from the footage that survives, it seems that the animators filmed the studio crew like composer Oliver Wallace for Sneezy and Dopey, but also Eddie Collins, who modeled for Dopey, Billy House for Happy and Doc, and even Marge Belcher who traded her Snow White costume to portray Dopey.
