MAHLI is located on the turret at the end of the robotic arm. That turret can be seen reflected in two places on the rover's "head". The large primary mirror of the ChemCam telescope (the Cyclopean eye in the top of the mast) contains an upside-down image of the turret. The lens on one of the Navcams reflects a mirror image of the turret.
A preliminary version of the same portrait is projected slightly differently, resulting in less distortion of the rover but significant curvature of the horizon: