Point-to-point comparison of surface brightness of mock halos in PSZ2 G120.08-44.41 (‘Sub. & Inj.’ scheme; central and peripheral injections are shown in the upper and lower panel, respectively). Values at 20 and 50 mJy are multiplied by a factor of 5 and 2, respectively, to match the injection at 100 mJy. The one-to-one line is plotted in black. Insets show the corresponding radial profiles, whose points are obtained as the average brightness of four 90°-wide sectors, whereas the shaded region represents their standard deviation. The point-to-point plots show that the lower the brightness and the injected flux density, the higher the scatter around the one-to-one line, indicating the progressive apparition of emission patches. Analogously, the radial profiles indicate that the scatter increases at larger radii and lower brightness.