Firmamento translates to "firmament" or "sky". It's a more poetic and grand word for the sky than the common "cielo", making it stand out.
In the song, the lyrics say, "porque me nada tan bello en todo el firmamento como tu reflejo" (because nothing is as beautiful in the entire firmament as your reflection). This elevated language emphasizes the profound beauty the singer sees in their beloved, comparing it to the vastness and wonder of the heavens.
Fondo Flamenco's "Me Encanta" is such a sweet and intimate song, all about those little things that make you fall head over heels for someone. The singer is completely smitten, and he's listing all the small, everyday moments that he absolutely adores about his partner.
He loves everything from the sound of her heels when she's a little mad and walking away, to her silly laugh that escapes in bed early in the morning. He finds her beautiful even when she's just woken up, with her "dos medios ojos medio de la cara" [two half eyes half on her face] and no makeup. It's clear he's deeply in love, even saying he'd "morir a dejarte" [prefer to die than leave you] and that he'd bring her a star from the sky if she asked. He just can't imagine a world without her, and that thought alone makes him want to "coge el alma y comienzo a gritar" [grab his soul and start screaming]. It's a really passionate and heartfelt declaration of love!