How did Mama encourage her daughter to apply for the job at the Pittman County Hospital? Why did she compare a person to a scarecrow?

The following quote is Mama's way of telling her daughter that she's the same if not better than anyone else. By pointing this out she convinced her daughter to go after the job.

“The way I see it,” she said, “a person isn’t nothing more than a scarecrow. You, me, Earl Wickentot, the President of the United States, and even God Almighty, as far as I can see. The only difference between one that stands up good and one that blows over is what kind of a stick they’re stuck up there on.”