Answer:
It shows not only Jem and Dill's relationship but their own charecterizations as well. Because Jem doesnt want him to hurt the turtle with the flame even though according to Dill it wasnt hurting him it shows that Jem cares and is thinking about the animal compared to Dill who is thinking immaturely and is assuming that hurting the animal is alright as long as hes not killing the animal he can have his 'fun'. it shows their relationship by showing just how close they are and how jem and dill are comfortable around each other, enough to banter and for Jem to stand up to Dill.
Step-by-step explanation: