Sometimes you don't want to be "literal" or photorealistic --you want to portray a scene or subject "artistically" and you take liberties in order to highlight and de-emphasize other less important aspects.
That said, some of the examples are funny, like where a shadow going up some steps stops short so as not to "overshadow" another subject[1] --whose shadow in turn seems to be perpendicular to the main shadow.
[1]Madonna and Child Enthroned with Saints” (detail)
That said, some of the examples are funny, like where a shadow going up some steps stops short so as not to "overshadow" another subject[1] --whose shadow in turn seems to be perpendicular to the main shadow.
[1]Madonna and Child Enthroned with Saints” (detail)