What helps connote luxury and self-indulgence on the part of the doctor?

THe quote goes, "But the trap was set. He couldn't take the chance. The doctor's eyes watered in their little hammocks" This is your quote from page 31.

Later, the doctor returns;

"The doctor also visits, and although Kino tells him that Coyotito is nearly well, the doctor claims that the scorpion sting has a curious effect that comes later and if he is not treated he may suffer blindness or a withered leg. Not sure whether or not the doctor is telling the truth, Kino nevertheless lets him see the baby. The doctor takes a bottle of white powder and a gelatin capsule, and gives Coyotito a pill. The doctor tells them that the medicine may save the baby from pain, but he will come back in an hour to check on him. After the doctor leaves, Kino wraps the pearl in a rag and digs a hole in the dirt floor where he conceals the pearl.

When the doctor returns, he gives Coyotito water with ammonia and tells Kino that the baby will get well now. Kino tells the doctor that he will pay him once he has sold his pearl. The neighbors tell the doctor that Kino has found the Pearl of the World and will be a rich man. The doctor suggests that Kino keep the pearl in his safe, but Kino says that he has it secure. The doctor realizes that Kino will likely look to the place where it is stored, and sees his eyes move to the corner where he had buried it. After the doctor leaves again, Juana asks Kino whom he fears, and he answers everyone."

"The doctor's newfound interest in Kino stems from a manipulative and dangerous greed. His visit to Kino reveals that he not only wishes to secure part of Kino's new fortune through the salary the doctor might receive for treatment but, as shown by the doctor's attempt to locate the pearl in Kino's hut, that he intends to steal the pearl. Steinbeck makes clear that the doctor does not visit Kino to cure his son; in fact, he indicates that the doctor's treatment of Coyotito might even be superfluous. The suspicious designs of both the doctor and the priest indicate that the danger that Kino faces is not from jealous neighbors who might use the pearl to escape their own poverty, but rather from those whose economic situation is secure and who merely desire greater luxury. Steinbeck thus uses the community reaction to the pearl as social commentary that critiques the ruling class for avarice and exploitation."