Final answer:
Marlow is distinct from other characters as his profession is detailed and his personal characteristics are thoroughly described, indicating his central role and depth.
Step-by-step explanation:
Marlow's depiction differs from that of the other characters in two main ways: First, Marlow is the only character whose profession is explained in detail, offering insight into his place in the story's world. Second, Marlow is the only character who is described with a significant amount of physical and personal detail, emphasizing his importance and complexity as a central figure in the narrative.
These distinctions set Marlow apart, highlighting his unique role and possibly his depth as a more developed character compared to the others.