You are braver than you believe, stronger than you seem, and smarter than you think.
This quote helps motivate me because it helps me realize that I'm actually good at things. I also use this quote to help me get through things when I'm nervous because it makes me think that I can do anything, despite the challenge. This quote has also shown me that I should believe in myself because nothing can stand in my way when I really try my best.
Stout pretty much means strong. When added to the word brave, it's clear that "our hearts" face fear head on, with a strong, unfearing willpower.
I always like to think of figurative meaning as deeper meaning: what is the narrator really trying to get the reader to understand? Once you have your answer, think about the key words in that excerpt that helped you uncover the figurative meaning-- these will always be figurative devices, so you're already half way through this question. (pro tip: stick to the text to uncover it-- don't stray to far from the information you are being provided)
Lastly, you're being asked to identify literary devices here, do you notice any symbols? Something that usually stands for something else that might relate to that deeper/figurative meaning? Also, think about how the way in which the author phrased these symbols impacted the overall deeper meaning.