Acomplejas comes from the reflexive verb acomplejarse, which means 'to develop an inferiority complex' or 'to feel deeply insecure' about something. It's a powerful word that describes a feeling much deeper than just being shy or sad.
In the song, Prince Royce sings "que te acomplejas de tu imagen" (that you feel insecure about your image). He uses this word to directly address the listener's self-doubt, making his message of self-love and acceptance in the chorus even more impactful.
Prince Royce kicks off this bachata classic by telling a girl he loves that he's heard she's insecure about her looks. His response is direct and sweet: he tells her to look in the mirror and see how beautiful she is without makeup. He doesn't care about appearances, singing, "Y si eres gorda o flaca / Todo eso no me importa a mí" [And if you're fat or skinny / None of that matters to me]. It's a powerful message about loving someone for who they are on the inside, not what they look like on the outside.
He builds on this idea with the song's main line, "Y el corazón / No tiene cara" [And the heart / doesn't have a face], explaining that love lives in the soul. To show he understands, he even admits his own insecurities, saying, "Aunque tenga cara de bonito me acomplejo yo también" [Even though I have a handsome face, I get insecure too]. It's a song dedicated to anyone who has ever felt they weren't good enough, with a promise that true love sees beyond the surface.