I don't remember the exact names of the 2 masks but they were the latest LR Classic "Improvements" to the app. They were really magical. They seem to have diasappeared with this latest LR update. Are they still available? Where? How?
They are in the new location, but they are still there: You should probably view one of the dozens of videos explaining the new features of this Masking tool, as the capabilities have increased tremendously.