Final answer:
The simile "like an overgrown child" suggests that Jalil is feeling immature and childish in the moment. He is upset and doesn't know how to express his emotions, so he resorts to acting in a way that is petulant and immature.
Step-by-step explanation:
The image of him digging at something with the toe of his shoe is also evocative of a child sulking or throwing a tantrum.
This simile is important because it reveals Jalil's vulnerability and inner turmoil. He is clearly struggling with something, but he is unable to articulate his feelings in a mature or constructive way.
This suggests that he is not as emotionally mature as he appears to be, and that he may be repressing some deep-seated insecurities or anxieties.
The simile also serves to characterize Jalil's relationship with Mariam. He is clearly not taking her seriously, and he is treating her with disrespect. This suggests that he does not value her opinion or her feelings.
This is a major problem in their relationship, and it is one that they will need to address if they want to have any hope of a future together.