Asomada comes from the verb 'asomar', meaning to peek out, lean out, or show oneself from a partially hidden spot, like a window or a doorway. It's a descriptive word that paints a quiet, almost cinematic image of someone appearing just enough to be seen.
In this song, the line "Asomada en la ventana con tu pelo negro" (Leaning out the window with your black hair) uses 'asomada' to freeze a single, tender moment in time. The word makes the image feel intimate, as if the singer is remembering one specific glimpse of someone they love.
Estopa's "Mañana Clara" is such a sweet song about being completely swept away by someone you see unexpectedly. The singer wakes up to a beautiful spring morning, feeling happy with "Las flores me decían que era primavera" [The flowers told me it was spring] and "Los pájaros que tengo dentro me cantaban" [The birds I have inside me were singing]. He's just enjoying the day when suddenly, he sees her!
It's like a dream, he says, seeing her on her balcony with her dark hair dancing in the wind. He's so captivated, he feels like he's still dreaming even when he's awake: "De esos que te despiertas y sigues durmiendo" [Of those where you wake up and keep sleeping]. She's become his muse, the one who inspires his melodies, even in his sleep. It's a lovely picture of love at first sight, or at least a powerful moment of infatuation that brightens his whole day.