There are several ways to approach this question:
You could focus on the clash of cultures within the village. How does the "old" village culture (represented by Baroka) clash with new "westernized" cultural ideas (represented by Lakunle)?
You could focus on the culture of Ilujinle as a whole, and then examine the ways in which it clashes with the culture of the stranger (the one taking photos for his book).
You could also focus on Sidi's bride price and the ways in which it creates conflict between the old and new cultures.