Incidence of the brightness model extension on the system parameter posterior probability distribution (PPD), using multipolar models. a), b) Marginal PPDs (68%- and 95%-confidence intervals) of and for the quadrupolar and octupolar brightness models, respectively. c), d) Marginal PPDs of ρ_⋆ and for the quadripolar and octopolar brightness models, respectively. These confirm the trend observed in Sect. 5.1 (see Fig. 6) towards larger and lower stellar density when increasing the complexity of the brightness distribution, i.e., when enabling more localized structures.