Illustration of how supergalactic coordinates distort the true position of galaxies. Here we show the distribution of exactly the same galaxies as in GAEA V2 but in a different coordinates system; the same area in the RA-DEC plane is shown in Fig. 1 (bottom-left panel). Left: Distribution of galaxies in supergalactic SGX-SGY-SGZ coordinates (includes elongation along the line of sight). Right: Same as left but in GAEA coordinate system x-y-z.