Try not to read too much into the title of this study! It simply refers to its manner of execution in that pairs of strings-1st/6th, 2nd/5th, 3rd/4th-are played together throughout the piece. The easiest way to play it is to use p (thumb) for the lower strings and i (index finger) for the upper strings. Major 7th and 9th chords add some harmonic color, while the repeated syncopation keeps everything moving briskly.
(Please consider supporting this site! Sheet music and tablature for Reflections and other guitar studies available here: Innovative Studies for Guitar – Volume 2)
Ken Pasciak 