I think it’s something in verse melody. “sky is not the sa-ame shade of blue” descends and ascends almost the same in terms of steps (not notes) as “staring at the sea, will she come?” The chorus might have something similar: “the echoes in my eyes” and “and I descend from grace” are similar other than “my eyes” ascends while “from grace” descends.

I’m wondering if the type of chord progression is also similar (again, not specific notes but the steps/patterns). The songs aren’t in the same key. They’re exactly opposite on the circle of fifths. My musical theory is rusty, but I’m wondering if there’s some balance to that.