Notes. The best fit model to the VLTI/MATISSE data yielded to a reduced chi-squared of 24. For each elliptical Gaussian disc component structure (EG comp.), the free-parameters are (x, y), PA, e, f and FWHM. They stand for the disc’s Cartesian coordinates on sky, its major-axis’ position angle, its elongation ratio, its flux contribution to the total flux in the image, and its major-axis FWHM size respectively. The upper table gives the averaged fitted value and the lower table gives the corresponding uncertainties for the fitted parameters (denoted with the prefix ‘Δ’ applied to the parameter symbol). ‘SE’ and ‘NW’ acronyms correspond to the south-eastern and north-western asymmetries respectively detected in 3 Puppis’ dusty disc.