She is an electronic butterfly, and she will say goodbye as soon as she turns it off.

"She is an electronic butterfly, and once it is turned off, it will leave forever." The next sentence can be "His soul is hanging like a star."

"She is an electronic butterfly that will never leave when it is turned off. Her soul hangs high like a star." Here, "she" is compared to an electronic butterfly, emphasizing its short and fragile life, and "he" is compared to a star, emphasizing the eternity and nobility of its soul. On the whole, it expresses the contrast and distance between two characters.