The movie is based 'loosely' on the career of Diana Ross and the Supremes. In one scene, the character, that would be Diana if an actual documentary movie, is impeccably dressed in a gown and very beautiful

jewelry. A close-up shot of her head includes a very close shot of her neck, including the necklace

clasp, which is a toggle clasp. Those clasp were not available in the 1960's or even the 1970's or the 1980's. They did not make the fashion scene until the last couple of years. That slip-up shouldn't have been missed, since the movie was a period piece.