Illustration of the disk structures and the pebble drift conditions of the two disks, with the millimeter-wavelength radial intensity profiles from J. M. Miley et al. (2024) on the right. The intensity profiles are extracted from the uv plane of ALMA observations. Sz 66 has a smaller, unstructured disk that facilitates pebble drift, enriching the warm and cold water reservoirs through the sublimation of ice mantles, while the gaps of Sz 65 prevent pebbles from crossing the water snow line.