Illustration of the projection effect in the strong lensing observables. We start with 3D density profiles of lens galaxies and project onto random directions 800 times. Dashed blue line marks the mean of θ_E under random projections. Orange solid line marks the θ_E of a spherical lens of the same mass. The projection effect in lensing is reflected by the scattering of θ_E around the spherical value.