Simplified graphical representation (not to scale) of the two possible scenarios that might explain the lack of observed polarized scattered light in the SPHERE/IRDIS images in the outer disk. Top panel: small grain depletion scenario is shown, in which small grains are present throughout the inner regions of a flared disk but are largely depleted on the surface of the disk at the location of the second ring. The larger grains are shown on the disk midplane, while the locations of the gaps are indicated by the white vertical bands. Bottom panel: increased settling scenario shows a double flaring structure for the dust and therefore for the scattering surface. A flaring outer edge with a small number of small grains remaining is necessary in both scenarios to account for the scattered light observed in HST images.