Graphical representation of the comoving volume of the 30° radius survey footprint, highlighting the four redshift bins bounded by redshifts 0.9, 1.1, 1.3, 1.5, 1.8, immersed in the comoving volume of the Flagship simulation (i.e. our reference) of EuclidLargeBox and of Geppetto simulation boxes. The Geppetto box is tiled a few times to cover the survey volume. For sake of clarity, the tiling is limited to the main replications. Here, the central axis of the footprint lies on the main diagonal of the box, but all EuclidLargeBox and most Geppetto boxes have random orientations of this axis.