When the principal begins his prom announcement, in the lunch room, something rolls underneath the chair he stands on, but it disappears when he is standing on it.
When Carter gives Rosie a "chore" to count the contents of the bucket in the bait shop, it clearly says "WAX WORMS", yet when she opens the bucket, it is filled with earthworms, not wax worms.
The cars in the movie have front state license plates, which are not required in Louisiana.
Chelsea is seen in the frozen yogurt store, and outside in the car in successive shots. These shots are not happening simultaneously, but indicate a passage of time to show how long Chelsea left Rosie to suffer in humiliation.
When the girls arrive at the bowling alley Ed says to Carter that he would get her shoes he said "5 1/5 coming up" but when they return the shoes the camera gets close to the real size on the shoe and it says size 7/8. Therefore Selena Gomez wears a size 7 or 8 shoe, not a 5 1/5.
When Chelsea and Brooke are in the gym reading the magazine article, as they walk away from the camera out the door you can see their microphone packs clipped under their shirts on their hips.
Large mountains are prominent behind Carter's house throughout the movie. There are no mountains in Louisiana.
During Rosie's first night in Louisiana, characteristic sounds of the Coqui frog ("Coqui, Coqui") can be heard in the background. This frog is native to Puerto Rico and is known to have spread to Virgin Islands, Dominican Republic, and Hawaii, but not Louisiana.
Outside the yogurt shop there's a sign that says "salida" which is "exit" in Spanish.
The metal boat at the lake has a Puerto Rico registration number which starts with PR-