Miley Cyrus told MTV News that this song is about the constant attention she gets. She explained: "'Fly on the Wall' is about the media. It's about how they think they know everything about me, when they don't. They want to be a fly on my wall and watch me 24/7."
Cyrus explained to MTV News why she released "7 Things" rather than this song as her first single from Breakout. Said the teenage singer: "It was originally going to be the first single. But instead, I thought '7 Things' was a better introduction to my entire album. 'Fly on the Wall' is very catchy and fun to dance to. It's one of my favorite songs on the album."
The song's music promo was directed by Philip Andelman, who a few months previously helmed the Jonas Brothers' "Lovebug" clip. Miley Cyrus was in a relationship with Nick Jonas for two years, before breaking up at the end of 2007. Andelman told MTV News of the coincidence: "I'm not sure if she did know I directed the ['Lovebug'] video and she didn't mention it on set." The director added that Cyrus definitely had a very strong idea of what she wanted in the clip. He explained: "I was told the song was a soft poke at the paparazzi that Miley is constantly surrounded by and that she was hoping for there to be some choreography in the video."
The video spoofs Michael Jackson's "Thriller" promo, but Andelman told MTV News that instead of zombies, everyone turns into Miley's worst nightmare: prying photographers. He explained: "I didn't want to do something too serious, as I felt it would come off as her being whiny instead of playful. The gist of the concept is that she and her boyfriend are on a date, leaving a movie, when suddenly, he gets overcome by some strange cough. Suddenly, he turns into a paparazzo and begins chasing Miley. Soon, she is backed into a corner with nowhere to turn and the paparazzi approaching, when suddenly, instead of attacking or photographing her, they break into choreography."
The phrase "fly on the wall" is commonly used to describe an unseen observer or listener. Its origins go back to 1920s America and it is most frequently used today to describe a form of documentary where the cameraman tries to be as unobtrusive as possible. One of the first citations of this phrase was in The Oakland Tribune, February 1921: "I'd just love to be a fly on the wall when the Right Man comes along."