She's just a girl, and she's on fireHotter than a fantasy, longer like a highwayShe's living in a world, and it's on fireFeeling the catastrophe, but she knows she can fly awayOh, she got both feet on the groundAnd she's burning it downOh, she got her head in the cloudsAnd she's not backing down
Metaphorically, 'hotter than a fantasy' describes the girl possessing an exceptional character and radiance, then again, 'longer like a highway' could entail that she has a multitude of positive qualities and strengths in her possession. Another Interpretation could also suggest that she is a person that has gone through many challenges and setbacks in life and 'longer like a highway ' could be placing an emphasis on the complexity and longitude of the challenges and setbacks that she has faced in her life, much like the layers of an onion.