When Helen is speaking with her dad after 'playing' with the carrot, the carrot changes from thick to thin each time they pan back and forth.
It's unbelievable that Helen, wearing only a shirt and no pants, would masturbate all over the house she shares with her father with no thought to her privacy, never closing a door or checking if she was alone, even though she was apparently too embarrassed to remove her shirt in the shower or even let it rise up.