Answer:
Emphasis is the part of the design that catches the viewer's attention. Usually the artist will make one area stand out by contrasting it with other areas. The area could be different in size, color, texture, shape, etc.
Explanation:
:)
The purpose was that <span>He wanted to create a work of art worthy of the church's holy treasures.</span>
I believe that element is called
flying buttresses.
Flying buttresses support the walls of a building and given that they are quite slanted, they seem as if they are forming an arch with that particular wall they are leaned against. I've attached an image of them for you to see what I mean.