Lentejuelas translates to "sequins". It's a vibrant and somewhat whimsical word that isn't commonly found in everyday Spanish songs, making it stand out.
In the context of "Todos Me Miran," the singer describes how, after breaking free from a toxic relationship, "la noche ya no era oscura, era de lentejuelas" (the night was no longer dark, it was made of sequins). This metaphor beautifully illustrates her transformation from feeling worthless to embracing her newfound confidence and sparkle, seeing the world as bright and glamorous.
"Todos Me Miran" starts in the wreckage of a relationship where someone convinced her she "no valía" [wasn't worth anything], leaving her crying at his feet and unable to recognize herself in the mirror. The turn comes fast: she lets her hair down, puts on heels, paints herself up, and walks out the door while he's still yelling after her, because "tus cadenas ya no pueden pararme" [your chains can't hold me back anymore].
From there it's a victory lap. The hook repeats "todos me miran" [everyone looks at me] as she takes back the attention she was denied, deciding on her own terms that she's beautiful, that she does what few will dare, and that whoever's watching with envy can keep watching — she's not shrinking for anyone again.