View the drawing of a woman looking back by Georg Hendrik Breitner (1857-1923). At the bottom the drawing is only schematically set up in loose straight lines. He also started with this ‘broken drawing style‘ in her upper body, but the drawing has already been further developed there.
If you want to draw a model, in real life or from an image, this broken drawing style is a good tool: you first draw the shapes/outlines schematically in loose (broken) straight lines. Later you can connect those lines and make nice curves where necessary. The broken drawing style was already used in the Renaissance (ca. 1350-1600). You can also see the use of the broken drawing style in Breitner’s sketch of a panther.