CreateScene() calls CreateCube(), which calls CreateCubeDetailed(), which calls AddTexture() only if the user has selected Texture in the UI:
void AddTexture(KFbxMesh* pMesh)
{
// The Layer 0 and the KFbxLayerElementTexture has already been created
// in the CreateCube function.
pMesh->GetLayer(0)->GetDiffuseTextures()->
GetDirectArray().Add(gTexture);
}