Answer:
In the book Marriage Is A Private Affair by Chinua Achebe, Nnaemeka is hesitant to tell his father about his engagement to Nene because he knows the issue is a sensitive one for him and he after he sends his father his wedding photo, his father cuts off Nene's face and sends it back to Nnaemeka. In his letter, his father voiced out his displeasure in a letter he sent his son when he said that the picture was unsolicited and he did not ask for it.
Nnaemeka's father was angry that Nnaemeka did not go according to the Igbo tradition of parent's picking a wife for him but went ahead to propose to Nene, an Ibibio girl so he was unhappy when he found out.