How can you use proportions to make decisions in art, design, and magazine layouts? give two examples?

Proportion is defined as the comparative relationship among various elements of  an image. 
Simply taking a picture of jpj or png format, if the side of the picture is drag in or drag out, then the picture got disturbed, but if the same picture is drag in or drag out by its corner, then the picture composition remains the same, and thus the proportions of all the pigments remains the same. 
Another example is that of using an equal proportionate amount of different colors in an image, otherwise the picture will not show its true essence and the proportionality factor among various colors of an image become the base of its originality.