Cassette refers to a cassette tape, an older form of audio recording. It's an interesting word choice because it's a bit anachronistic in modern music, making it stand out.
In the song, Kenia OS sings, "Tú no va' a poder cambiarme el cassette" (You won't be able to change my cassette). This is a metaphorical expression meaning "you won't be able to change my mind" or "you won't be able to change who I am," drawing a clever parallel to how a cassette's recording is fixed and unchangeable.
In "Llévatelo," Kenia OS sings about being unimpressed by a man who is all style and no substance. At first, she admits his "doll-like face" and charming words blinded her, but she soon realizes he has nothing interesting or intelligent to say. His mind is as empty as his promises are flashy.
This song is a powerful anthem of self-worth. Kenia OS rejects the man's attempts to win her over with material things like Gucci, Prada, and trips to Milan or New York. She makes it clear she can buy those things for herself, declaring, "My mind defines my power." The track serves as a reminder that true value isn't in expensive brands or a pretty face, because as she sings, "all that glitters is not gold."