Near the end of the movie, Maggie takes the guitar that was immediately before played by the left-handed caracter (it means that he had his right hand on the fretboard), and starts to play it in the right - handed manner (her LEFT hand is on the fretboard). It is nearly impossible for a right - handed player to normally play the guitar that was set up for a left - handed player since the string setup and tune is mirrored!

Unless you happen to be Jimi Hendrix, of course.