Population results based on mock mass profiles following the ellipticity and position angle variations observed in local galaxies, using the Kormendy et al. (2009) sample. The nine fiducial galaxies are represented with different symbols, filled when the considered Einstein radius is 2″, and empty for θ_E = 1″. Each galaxy is used to create three types of mock mass profile: the twist case in which only the position angles follow the original galaxy profile (red), the ellipticity case in which only changes of ellipticity are allowed (green), and the twist + ellipticity variation case (blue). The different mock images, created with the lens mass profile that lenses a circular Sérsic background source, are modeled with a PEMD + shear lens model and a circular Sérsic for the source model. The definition of the first nine quantities is listed in Table 1. The χ² is the reduced imaging χ² of the fit. The last four quantities are defined in Sect. 2.2.3. Since these latter quantities are specific to the different galaxies and do not involve any modeling, they are plotted in black. The diagonal cells are KDEs of the marginalized quantity. Only the fits with χ² <  1.5 are considered for the KDE distributions.