I think it's about a girl, so desperate to be accepted, taht she's making herself into something else. But by doing this, even though she has all the "friends" she could ever want, she'll "never be quite satisfied" because she isn't living up to who she really is.
"There's not much left inside your chest, but it's worth much more than what you see" is saying, you've sort of sold your soul to be accepted, but it's what's on the inside, and how big your heart is, that counts, not what you look like and how many friends you have.
I think it's about a girl, so desperate to be accepted, taht she's making herself into something else. But by doing this, even though she has all the "friends" she could ever want, she'll "never be quite satisfied" because she isn't living up to who she really is. "There's not much left inside your chest, but it's worth much more than what you see" is saying, you've sort of sold your soul to be accepted, but it's what's on the inside, and how big your heart is, that counts, not what you look like and how many friends you have.