Why can having an understanding of imagery, proportion, balance, and design you to evaluate the validity of an artwork?

Because they are helping us to estimate the artwork at the first look

Explanation:

When we are looking at some piece of art, the best way to recognize experience and effort of the artist is to understand imagery, proportion, balance, and design because it is easier for us with that knowledge to estimate certain style, period or skills that artist was trying to show to people.

you make more money, you can get a better job, you have a better education, you are wanted more by most employers.

the above mentioned statements talks about the creativity of an artist and to what extend they can utilize and experiment on the objects provided.   differing size and subjects are given so that an image of wisdom is created. displaying a transition from light to dark in something by darkening sections in order to create a shadow. and lastly, putting bits and pieces together to formulate a new image.