In multiple points perspective, why do the vanishing ponts not appear on the canvas itself?

based on the images pictured above, the major difference between the two cathedrals: the cathedral of notre dame and the amiens cathedral, is that the cathedral of notre dame emphasizes the horizontal lines while the amiens cathedral emphasizes the vertical lines.

i think these large heads represent their gods and i do think they were worshiped by the people. if there was only one head and no heads around it i think it would be monotheistic but if there are several heads close to each other it could be polytheistic.