I just love how he seems extremely interested in her ear, in that "I've seen this ear a million times, I've touched it, contemplated it, just like I'm doing now, and yet, it still fascinates me as much as it always has, because it's part of Her" kind of way. It's like an interested, idle curiosity of something that might hold little interest to another, but has a universe of meaning to him. And she, almost seeming "board" at first glance, puts a silly heart in lipstick on his gasmask. It's the fact that it isn't an unusual occerance that makes it so sweet, it's something she does because she loves him, and she enjoys it for it's simple being, as aposed to the exciting novilty of being silly.
I just love how he seems extremely interested in her ear, in that "I've seen this ear a million time