What is ironic about Hassan's birthday present?

Hassan's birthday present is ironic because, instead of receiving something he truly desires or values, he gets a gift that highlights his social status and the disparity between him and his friend, Amir. The present, a new kite, symbolizes the competitive nature of their friendship, yet it ultimately serves as a reminder of the betrayal and jealousy that defines their relationship. This contrast between the gift's intended joy and the underlying tension makes it a poignant reflection of their complex bond.