The Marian image at the center of the prodigy dates back to the mid-15th century. Tradition has it that it was painted in 1456 by the young Agostino da Pavia. Agostino frescoes the image as a gesture of thanks to the Virgin whom he had invoked while riding across the waters of the Ticino, into which he was about to sink. Having overcome the danger and moved along the banks of the river, the young painter saw a humble votive shrine, which he decided to decorate and embellish with an image dedicated to Mary
The painting presents the Virgin seated in the chair, covered with a large dark red cloak, with a green lapel. The headdress is of the same fabric, tied around the neck and as if "stopped" by the index finger of the right hand of the Child Jesus, which the Virgin carries standing on her knees.
The right hand of the Madonna holds a book resting on her knees; the left hand supports the Child, with sweet eyes, and dressed in a short white tunic wrapped around the waist.