Projected surface mass density of a dark matter halo with mass log M₂₀₀ = 13, contracted following the procedure described in Sect. 3.2 (magenta line). Cyan line: original, pre-contraction dark matter halo described by an NFW profile. Blue dotted line: gNFW profile fitted to the contracted dark matter halo. Black line: stellar component of the lens, consisting of a de Vaucouleurs profile with total mass log M_* = 11.5 and half-light radius R_e = 7 kpc. The values of the halo mass, stellar mass, and half-light radius are close to the median of the distribution of the simulated lens sample.