A single labia minora conceals the labia minora.
In movie 4, even when her legs are spread and her labia majora are open, her labia minora remain closed, but a milky fluid is already seeping from the small gap.
In movie 6, even when she spreads her legs wide and opens her labia majora wide, her labia minora remain tightly closed, but in the end, she inserts her fingers into her vagina and stimulates herself, letting out a moan as she finishes.
Her longing expression at the end is also wonderful.