Comparison between the BUG multiangular measurements and the retrieved Hapke model for the Mars analog at 550 nm. Top: measured radiance factors and predictions from the posterior-median multiangular retrieval, evaluated at the same incidence, emergence, and phase angles as each laboratory measurement. Bottom: fractional residuals, defined as 100(r_obs − r_model)/r_obs. The dashed horizontal lines indicate ±10% residuals. The comparison provides a direct assessment of the ability of the retrieved photometric solution to reproduce the measured angular scattering behavior.