Painting on glass is a popular Polish form of folk art by which the artist paints a picture on the reverse side of a glass surface.
By far the most elaborate szopkas are those from the city of Krakow.  Modeled after the great Mariacki (St. Mary's) basilica in Krakow's main square, the szopka is decorated with brightly colored foils and is the background for its most important feature, the Christmas Nativity scene.
Painting the Szopka Krakowska on the reverse side of glass is a specialty of master artist Janina Oleksy-Lew. All pictures vary.  No two alike.