Why? What's the implication? The scene really threw me off as it felt like it came out of nowhere.
shareShe was aroused by the killing that she assisted earlier. It revealed her dark side.
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She and her uncle share some of the same nature.
The masturbation was pretty much her opening up to something inside herself that she had not explored yet.
Which is why this scene is preceded by previous scene were she started cracking an egg, also the scene where the uncle finds an egg under the bird that she killed.
By the end of the movie she has fully grown into a characteristic that she had inside her all along. And what she does with this awakening is up to her.
Zardoz (1974) has spoken!
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