A commenter on youtube said, "This is one of the most disturbing videos.... going down on the yellow flower, the giant pink vulva flower... And the lyrics. The lyrics are heartbreaking really. You can never be the only girl in the world and you can never be the best. This, like all her videos is sending the message "I'm a hot vag, use me and I'll imagine its love," but this one seems more self-aware and pained. I'm sure no one reading this is going to get what I'm saying though... It is sickly mesmerizing."
But she's saying "I want you to make me feel like I'm the only girl in the world." I don't think she's implying, "I want you you to tell me I'm the only girl in the world and mean it absolutely." She's talking about a feeling, not a reality.
This video is incredibly different from her pagan Rockstar 101 video. That video screamed "Fuck off. I'm in control now," while Only Girl in the World says, "Look at me! I'm a womaaaannnn! Deflower me!" She would prefer it if you loved her like a "hot ride," though. So, if you can't love her like you love your car, I suppose you're out of luck.
I must say that I think her sacrificial virgin bra-and-long-skirt at the end is a bit strange. Her red hair, though, ugghh, amazing. I want. Apparently I can't write proper sentences when I want bright red hair.