That sticker is simply a Florida state outline decal.
It’s a minimalist silhouette of the state of Florida — people commonly put these on cars to show:
- They’re from Florida
- They lived there before
- They love the state
- It’s their home state
There’s no hidden symbol, political meaning, or secret message. It’s just a state-pride sticker.
So if your girlfriend brought it when you moved in, she likely has a connection to Florida (grew up there, lived there, family there, etc.).
If you’d like, I can also point out exactly which parts of the shape represent which areas of the state.