Nsibidi
en.wikipedia.org
en.wikipedia.org
It really isn't. But people outside Nigeria are generally barely aware of the existence of southeastern ethnic groups that are not Igbo, to talk of interested in their contemporary lives.
They could have tried to build a relationship/collaborate with (especially older) Ejagham or Annang people. But that would take time, effort and actually caring about bridging the gap, not simply aiming to make a buck.
< Examples follow >
Toilet soap
Ummmm?