I would say that it depends on the audience. Personally, a debate regarding ethics and moral dilemma is interesting. Read The Fat Man and the Impending Doom. It's just one paragraph so it's not going to bore audience.
https://thedailydilemma.wordpress.com/2007/06/18/fat-man/
I believe that this type is a lecture-forum discussion.
Answer:
I believe it is a metaphor for the fact that the backpack is heavy.
Explanation:
The purpose of a descriptive essay is to reveal the meaning of a subject through detailed, sensory observation of course.
