Differences in stellar λ_R between the pairs of twin galaxies. The best twin of each AGN is indicated with a green circle. Each column corresponds to an active galaxy and each symbol to the difference in λ_R with each of its twins. The colour code indicates the difference in ellipticity (ϵ_AGN − ϵ_twin, see Table 1). Error bars correspond to propagation of the individual uncertainties (see Sect. 3).