What is it something that makes her laugh?

The memory of the big,elderly man making a game out of carrying a parcel is what made her laugh and also because her elder brother narrated the story in comic detail. But it was not an amusing story, the man was not being funny when he carried the package in the way where he did not want it to be contaminated by Annan, her brother. He was an upper caste man who believed the people who belonged to the lower castes like Anna should not touch them or they would pollute the 'pure' castes. That is the reason he was carrying the package by its string.