Comparison between the asymmetric and spherical onion-like models. The asymmetric layers are shown in the blue solid curves, while the spherical layers are shown in the magenta dashed curves. The left panel shows the cross-section of the models across the center and within the sky plane. The right panel shows the cross-section along the main cut (NE-SW direction) and the line of sight, where both asymmetric and spherical models are identical on the NE side.