Lyric discussion by Jubispo 

When the chorus comes, it just sounds like he's talking about, well, mona lisa herself. Or comparing a very mysterious girl to monalisa. "You're guaranteed to run this town" - one of the things that brings people to Paris is her portrait "I'd pay to see you frown" - she is famous for her facial expression, a mix of frown and smile...and you do have to pay to see it

"He senses something, call it desperation Another dollar, another day And if she had the proper words to say, She would tell him But she'd have nothing left to sell him"

he keeps going back to try to understand her facial expression, but can't, and If she were to tell him he'd have no more admiration for that mysteriousness...

that's how I first understood this song, but the ideas of a couple fighting or a prostitute are pretty interesting as well.

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