Schematic illustration of the interaction between polarized thermal emission of an elongated prolate dust grain (orange) and their dichroic extinction (black). This illustration is also valid for oblate dust grains, because the key effect is the same. E is the electric field vector component parallel or perpendicular to the magnetic field B. The critical distance s_crit is taken from Eq. (13), P_l is the degree of polarization and θ is the polarization angle relative to the x-axis. The radiation of the absorbing dust grains (black) is not taken into account.