最近经常听到别人放的一首英文歌，男声，歌词里有nobody求告知

What Makes You Beautiful
One Direction
You're insecure
Don't know what for
you're turning heads When you walk through the door
Don't need make up
to cover up
Being the way that you are is enough
Everyone else in the room can see it
Everyone else but you
Baby you light up my world like nobody else
The way that you flip your hair gets me overwhelmed
But when you smile at the ground it ain't hard to tell
You don't know Oh oh
You don't know you're beautiful
If only you saw what I can see
You'll understand why I want you so desperately
Right now I'm looking at you and I can't believe
You don't know Oh oh
You don't know you're beautiful Oh oh
That's what makes you beautiful
So c-come on
You got it wrong
To prove I'm right
I put it in a so-o-ong
I don't know why you're being shy
And turn away when I look into your eyes
Everyone else in the room can see it
Everyone else but you
Baby you light up my world like nobody else
The way that you flip your hair gets me overwhelmed
But when you smile at the ground it ain't hard to tell
You don't know Oh oh
You don't know you're beautiful
If only you saw what I can see
You'll understand why I want you so desperately
Right now I'm looking at you and I can't believe
You don't know Oh oh
You don't know you're beautiful Oh oh
That's what makes you beautiful
Na na na na na na na na na na
Na na na na na na na
Na na na na na na na na na na
Na na na na na na na
Baby you light up my world like nobody else
The way that you flip your hair gets me overwhelmed
But when you smile at the ground it ain't hard to tell
You don't know Oh oh
You don't know you're beautiful
Baby you light up my world like nobody else
The way that you flip your hair gets me overwhelmed
But when you smile at the ground it ain't hard to tell
You don't know Oh oh
You don't know you're beautiful
If only you saw what I can see
You'll understand why i want you so desperately
Right now I'm looking at you and I can't believe
You don't know Oh oh
You don't know you're beautiful Oh

what makes you beautiful？