She uploaded the photo on Instagram and captioned it "Geekin" out at #Disney #d23expo.
In the new photo, the 32-year-old actress' hair reaches down to her ears.
The second photo shows an almost full length view of Nyong'o, sporting a goofy expression and wearing a green, white and black striped dress as she holds up two movie posters - "Star Wars: The Force Awakens" and Disney's "The Jungle Book" - which she was in town to promote at the fan expo in Anaheim, California.