The isometry group of the classical Lawson embedded minimal surface ξ_{2,1} ⊂ S³ of genus 2 is isomorphic to the group D₄ × S₃, where D₄ is the dihedral group of order 8 and S₃ the permutation group of order 6. Iso(ξ_{2,1}) has a subgroup of index 3 isomorphic to the bidihedral group D_{4h} = Z₂ × D₄. We will explain how to prove that ξ_{2,1} is the unique closed embedded minimal surface of genus 2 in S³ whose isometry group contains D_{4h}. This is a joint work with J. Pérez