Desveló comes from the Spanish verb 'desvelar', which has a clever double meaning: it can mean 'to keep someone awake' or 'to reveal or unveil something hidden'. That double edge is exactly what makes the word so striking in songwriting.
Dani Martín sings "Robando el sueño, así nos desveló" (Stealing the dream, thus kept us awake), and the line plays on both senses at once, suggesting that losing sleep over someone also uncovers something true about the relationship. One single verb carries the whole emotional weight of the line.
"Caminar" opens with a search: "Busco el beso, la revolución" ("I search for the kiss, the revolution"). Dani Martín wants a message that "hable más de amor" ("speaks more of love") in a world he pictures as already broken, and he asks for the courage to face down the wolf that lied to everyone and hear it say sorry to the child it fooled.
The chorus strips all of that down to one word: "Caminar" ("Walk"). Just "poner sonrisa a cada paso y respirar" ("put a smile on every step and breathe"), because "será bonito lo que quede por llegar" ("what is yet to come will be beautiful"). He tells himself to look straight ahead and never lower his gaze again, and to "Retirar" ("remove") whatever ugly mask is holding him back. September can try to take his hope away. He keeps walking anyway, and the song never once raises its voice to make that point.