Rompecabezas literally translates to "head-breaker", but it's the common Spanish word for "puzzle". It's an engaging and visual word that isn't found in every song.
In "Vibra Perfecta", the singer uses rompecabezas to describe how he and his partner fit together perfectly, like pieces of a puzzle, to complete his life. This metaphor beautifully conveys the idea of finding a missing piece and forming a complete picture.
Emmanuel Cortés builds this whole song on one image: two hands that turn out to be the matching pieces of the same puzzle. Before her, everything runs the wrong way. "Todo iba cuesta abajo, algo aquí me trajo" (Everything was going downhill, something brought me here), and "Andaba sin rumbo cuando no te conocía" (I was aimless when I didn't know you). He lets the cold do the work of the loneliness, "Me sentía vacío, me quemaba el frío" (I felt empty, the cold burned me), until "Pero tú llegaste pa' cubrirme con tu abrigo" (But you came to cover me with your coat). A coat is a small, ordinary thing to hang a love song on, and that is exactly why it works.
Then comes the admission. He is honest about what the earlier relationships were, "Que solo buscaba alguien para entretenerme" (I was just looking for someone to entertain me), and insists this one is a different order of thing: "Perdidamente, no como otras veces" (Hopelessly, not like other times), "Y ahora sí me clavé" (And now I've really fallen hard). The puzzle line is the one to wait for, "Que mi mano y tu mano formaran la pieza correcta" (That my hand and your hand would form the right piece), and just past the halfway mark he steps out of the song altogether to say "Y ahí te va, chiquitita" (And this one's for you, sweetheart) and name himself. It is a norteño love song that never reaches for anything grander than a coat and a jigsaw, and it does not need to.