This is a pattern for a bow that is symmetric not only along the short axis (left-right), but also along the long axis (up-down). This symmetry (called helical) makes it look very realistic.

The bow is made by crocheting on both sides of a base chain (upwards and downwards) to create a tube. The tube is compressed in the middle by weaving in the yarn tails through the middle stitches and pulling them tightly. The middle is then hidden behind a narrow crocheted strap.