Question

How do the physical descriptions of the characters help us to understand them? for example, how is tubâs obesity relevant to his character?

Answer 1

Because it is a common perception that some physical attributes is associated with certain characteristics.
For example, obesity usually associated with laziness and unassertiveness because of most people aware that it took discipline to obtain good body.
But on the contrary, people also usually associate obese people with kindness and heartwarming nature