Radial vs. angular distribution of particles in the orbital plane for experiment O7 for the Carina-like progenitor in the static case (left), time-dependent case (middle), and static case with the same initial action-angle distribution as in the middle panel. The dashed curves show the orbit of the centre of mass of the system integrated in the present-day potential for the left and right panels, and in the evolving potential for the middle panel. For the static cases, the variations in the apocentric distances are a reflection of the energy gradient present along the stream, while a second effect is present in the middle panel because of time evolution. In this case, the difference in angular location of the apocentre is also much more pronounced and systematically increases for older wraps.