Perhaps the most unexpected fashion icon of the year has just added another glossy credit to her name. Chimamanda Ngozi Adichie, the Nigerian-born novelist and feminist known for novels like “Americanah” and “Purple Hibiscus”; recipient of a MacArthur “genius” grant, the O. Henry Prize and the National Book Critics Circle Award (among others); and author of a viral TED Talk, “We Should All Be Feminists,” which has been viewed over three million times since its delivery in 2012 as well as sampled by Beyoncé, is now the face of No7, the makeup brand owned by the pharmacy chain Boots.

This follows her front-row appearance at Dior’s spring runway show, where she was both guest of honor and inspiration — printed across one of the T-shirts was the title of her TED talk — as well as her inclusion on Vanity Fair’s International Best-Dressed List.

Though her feminism may seem at odds with this embrace of the fashion world, Ms. Adichie has argued, most recently in a letter she posted to her Facebook page about raising a daughter, that diminishing things that are considered feminine, such as makeup and fashion, is part of a culture of sexism. As to why, consider the following. (The conversation has been edited and condensed.)

How have your feelings on makeup evolved?

In general, the cultures that I know — Nigeria, the U.S., the U.K, Western Europe — all largely judge women quite harshly for appearances. But in Nigeria, there’s a slight difference. There isn’t much of a judgment if you’re an accomplished woman and seem to care about your appearance.