Comparison of non-expanding (right panels) vs expanding (left panels) for β_exp = 0.1. Top panels: evolution of the SEDs after the flaring stage, where the blue colour indicates to the non/pre-expansion case, and orange indicates the expansion. Second row of panels: evolution of the flux density (F_ν). Three bottom panels: merged light curves of both the flaring and the long-term simulation in the Fermi-LAT band, and at 5 and 40 GHz. The red dashed lines mark the light-curve segment belonging to the flaring stage and the orange vertical dashed lines mark the beginning of the expansion.