How does Harkhuf's autobiography illuminate early Egyptian interest in Nubia

According to Harkhuf, the Pharaoh was interested in seeing the Pygmy that was going with Harkhuf. He tells him that he will reward him more than anyone has ever been rewarded and that the Pygmy is to be protected at all times, as much as having 10 people around him while he sleeps. To him it was the worthiest thing ever.