A fading smile can mean one of two things. Either he's not doing a good enough job of keeping her mind off of things, or the task itself was too much for him to begin with.

Mike watches her closely. He doesn't know what to say, because he doesn't know what she's feeling. He wonders if being human would help, or if this is something that would always be just beyond the scope of understanding.

After a few moments of silence, Mike offers her his hand.