V-band face-on projected surface brightness distribution of a symmetric (left) and lopsided (right) galaxy, considered as examples of the classification made by A₁. Their respective A₁ value, ID (as in TNG50-1), and redshift snapshot are plotted on the upper side. On the lower left, the box size considered for each galaxy is also plotted. For both images, the dashed cyan line represents the radius R₅₀ and the solid cyan line represents the radius 1.4R₉₀, which are the limits of the radial interval used in the Fourier decomposition.