This section allows you to customize the swatch color/image on your product page. The available custom settings include; Swatch style, Border color, Variant name tooltip and Image position. You also have a nice preview section to the right, so you could see the effects of each changes in real time.
You can set the swatch style to either circle or square. Set the swatch size to Big, small, medium or custom size. Set the Border color when normal or active.
You can enable or disable the name tooltip and lastly, set the image position to either fit, top, buttom or center.
A GIF image showing the Swatch Customizer option.