When he visited the region in 2014, he spent time asking people all about the masks: their meanings, the tribes they belonged to, the symbolism behind them.
"It's more than a mask. ... I discovered that it's symbolic," Harbi said. "It's groups of people that are living through these masks, and they have a significance -- a social and cultural meaning and significance."
For nine months, he worked on his photo series, "Woongo, Behind the Masks." "Woongo," which means masks, is a word from the Moore language in Burkina Faso.
"After a while, I had a selection of like 20 masks with different significances and meanings, and I just tried to begin to play with that," Harbi said. "I took the masks and when I met people, I made an appointment with them and I tried to explain to them: 'Do you mind if I take a picture (of you) with this mask? Because I think that the meaning of this mask is a little bit similar to your life, to your profile.' "
There is thought and creativity behind every image. For the photo of Mary and Marian -- No. 10 in the gallery above -- Harbi asked if he could photograph them wearing masks of the moon and the sun.
" 'You are twins, and for me the moon and the sun are like twins,' " Harbi said he told them. " 'After the sun, there's always the moon, and after the moon, there's always a sun. One cannot live without the other and they are always linked forever.' And they liked the idea, the poetry of this idea."
Harbi adds that the image of Mary and Marian also tells a story about Accra, the Ghanaian capital where the twins often model for different "trendy, modern magazines." Just as the moon and sun change our world from nighttime to daytime, Accra is experiencing a cycle of change from traditional to modern.
Underlying Harbi's photo series is his recognition that Africa today and throughout history has long been portrayed to the world from a postcolonial lens -- a lens that not only shows narratives of suffering and hunger, for example, but often exoticizes the continent and its people.
"For me, it opens a broad spectrum of reflection about the image of Africa -- how is Africa represented, has been represented, has been broadcasted, has been framed and photographed," he said. "I want to break the cliche. ... To make people maybe understand that Africa is not an exotic idea. It's not just a mask that you can just put in your house as a decoration."
There are similarities between the countries Harbi traveled to -- Ivory Coast, Ghana and Burkina Faso -- but he says it's important to recognize that each place is diverse in its own right.
"The way that Africa is divided now as countries doesn't reflect the reality of the tribes and the geographic and social organizations and countries," he said. "To see behind the mask is not just seeing the people behind the masks, (it's) seeing Africa differently."
Harbi is from the North African nation of Tunisia, and says that doing this photo series was also a personal exploration of his own identity.
"I think that we, North Africans, ... we look always north, north, north," he said. "We have a lot of things to win and to understand and to gain (by) looking south. ... To go and meet people and understand them and work with them. ... (Africa is) a part of our identity and I think it's time to look south and to re-explore narratives, to tell stories differently, to play with form. There (are) no rules."