DM surface density is shown for the primary subhaloes simulated with CDM (the two left columns) and fSIDM with cm² g⁻¹ (the two right columns). We note that the colour scaling is logarithmic. The shapes were measured within a volume of V = 4/3 π (0.032 r_1/2)³ (odd columns) and V = 4/3 π (0.0105 r_1/2)³ (even columns). They are illustrated with coloured ellipses. The haloes are shown face-on according to the measured shapes. We matched the haloes across the simulation, where matched haloes are shown in the same row and the same colour is used for the ellipses.