Magnification maps normalised to the mean macro-magnification, ⟨μ⟩, for images A and B with the 500 pairs of tracks of the best fitting model. These tracks are randomly oriented, and their microlensing difference histograms were averaged to build the model histogram. The radius of the red circle at the bottom of each map corresponds to the inferred half-light radius of the source (i.e. 0.7 R_E or equivalently 6.4 light-days).