Results of the final MCMC run, used to sample the possible shape and orientation of an ellipsoidal Dimorphos, with the constraints obtained on its projection at the occultation epoch (Fig. A.1). The ellipse semi–axis, the longitude and latitude of the sub-Earth point, and the position angle of the N pole on the sky are represented. The ellipsoid axis and the position angle are reasonably constrained. The sub-Earth point approximate longitude and latitude, for symmetry reasons, have a double peak distribution. We define the latitude as the angle at the ellipsoid centre with respect to the (a, b) plane. The longitude origin is taken in the direction of the longest axis, a. The origin of the rotation Ψ is along the major axis of the projected ellipse, at position angle η = 87° .6.