Songfacts®:

• A mirrorball or discoball is a spherical mirror-covered object that reflects light directed at it in many directions, producing a complex display. A standard piece of equipment in discothèques, it typically hangs above the dance floor to reflect light. During this folk-pop song, Taylor Swift compares herself to a mirrored disco ball hovering above a dance floor.
  
  She flaunts her confidence in her relationship.
  
  Spinning in my highest heels, love
  Shining just for you
  
  The singer can become anything she wants for the sake of romantic fulfillment,
  
  I'm a mirrorball
  I can change everything about me to fit in
  
  And she shatters like glass when her heart is broken.
  
  Shimmering beautiful
  And when I break, it's in a million pieces
• Swift wrote the song with frequent collaborator Jack Antonoff, who contributed to 11 out of the 18 tracks on her previous Lover album. She described the producer as "musical family."
• The British band Elbow recorded a song titled "Mirrorball" in 2008. In their instance, Guy Garvey is singing about waking up the day after he fell in love; he steps out of his house into the street and feels like dancing underneath the moon as if it were a mirror ball.
• Taylor Swift had planned the Lover Fest concert tour in support of her Lover album. She scheduled the tour to begin on April 5, 2020, but following growing concerns over the COVID-19 pandemic, all dates were either canceled or postponed. Swift wrote this song right after she found Lover Fest wasn't happening.