  This paper aims to provide a description of totally isotropic Willmore
two-spheres and their adjoint transforms. We first recall the isotropic
harmonic maps which are introduced by H\'elein, Xia-Shen and Ma for the study
of Willmore surfaces. Then we derive a description of the normalized potential
(some Lie algebra valued meromorphic 1-forms) of totally isotropic Willmore
two-spheres in terms of the isotropic harmonic maps. In particular, the
corresponding isotropic harmonic maps are of finite uniton type. The proof also
contains a concrete way to construct examples of totally isotropic Willmore
two-spheres and their adjoint transforms. As illustrations, two kinds of
examples are obtained this way.
