[That is perhaps the one thing Steve does seem to immediately understand. Not why or how or anything like that. Just the simple sentiment of wanting to be acknowledged.]

I'm proud of you.

[And, because that hasn't gotten through to Loki before:]

Even if you're afraid, you've managed to step forward. You came to me when you knew it wouldn't be easy. You're kind, even if it's something you don't think about. You go out of your way to make people you care about happy, and even if it's just a few people, even if it's one person, that is still a generous thing to do. You don't have to outshine anyone else to be good enough. You are already doing those things as Loki. No one asked you to. That came from you.