Esfumado comes from the verb esfumar, meaning "to blur, fade, or soften". It's a beautifully poetic word, closely related to the Renaissance art technique sfumato, used for creating a soft, hazy, or smoky transition.
In the song, Natalia Lafourcade sings, "Lo que un día construimos se ha esfumado" (What we once built has vanished). She uses this word to describe how their relationship didn't just end abruptly, but delicately dissolved into nothing, like a drawing slowly fading away. This poignant imagery makes it a truly memorable word for expressing loss.
This song is a beautiful, bittersweet look at the end of a relationship. Natalia Lafourcade isn't angry or placing blame; instead, she's taking stock of what's been lost. The central idea is right in the title: "Lo que construimos" (What we built). She repeats that this creation "se acabó" (is over) and "se lo lleva el viento" (the wind carries it away). It's a sad acceptance that something they worked on together has simply vanished.
Even though the story is over, the memory of her ex is still very present. She calls him "un fantasma conmigo caminando" (a ghost walking with me). She wants to be clear that the relationship was important, telling him, "No creas que no valió la pena" (Don't think it wasn't worth it). She even admits she saw a real future, calling him "una apuesta de largo plazo" (a long-term bet). The pain of the breakup is real, but she sees it as something unique to them, saying "aunque nos duele es sólo nuestro" (even though it hurts, it's only ours).