Relative difference between the signal measured in the 4224 Egretta mocks (realistic mask and depth variations) with the signal prediction of OneCovariance code. The colour bar indicates the different unique tomographic bin combinations, the same as in Figure 3. The dashed lines show ξ₋ and solid lines ξ₊. The grey band indicates a five per cent relative difference. The different plots show varying settings in the OneCovariance code. In particular, we distinguish whether the averaging over the θ bin (see Equation (61)) is carried out and if the pixel window due to the finite resolution of the healpix map is taken into account, i.e. damping power on small scales (N_side correction).