I'm also curious how differently this phrase is perceived when the scene is replayed, when you already know that everything will be fine. I wonder, if Astarion is a narcissist and admires himself, what would be the name of a character who admires Astarion himself in the same way?
Echo The myth of Echo and Narcissus from Ovid's Metamorphoses, I really love that subject in art.. Waterhouse, Poussin, Caravaggio. Well, to admire someone could mean, you wish to be some part of him or his character traits or to just think about how would it be to be like him - well just in fantasy, maybe some kind of this? Sometimes we like to see some character traits of others in ourselves and sometimes we like to see our character traits in others, everyone can be a bit self centered. I like playing two contrasting characters (Astarion vs Tav): selfish, evil, extroverted, experienced, strong vs. empathetic, good, introverted, shy, inexperienced, weak - like enemies to lovers. They complement each other completely like a balance.
That's exactly how I played my Tav. Not weak, but kindhearted, a little annoyed by Astarion's impatience and snide comments, but finds something oddly charming about them. I'm not a big fan of romance stories in general. They each have something to learn from each other.
ETA: I have a good book recommendation for anyone who likes the idea of a more altruistic Tav paired with a cheeky, unapologetic Astarion. It's a bit older so you may have trouble getting your hands on a copy, but it's a YA novel called Companions of the Night by Vivian Vande Velde. It's not a sweeping epic fantasy romance (the whole thing takes place in a small town in upstate New York over the course of a couple of days) but it's about a young woman who saves a young man from a group of people who claims he's a vampire, only to find out he actually is one. Probably one of my favorite books since I was a preteen and exactly the dynamic I pictured between my Tav and Astarion.
The myth of Echo and Narcissus from Ovid's Metamorphoses, I really love that subject in art.. Waterhouse, Poussin, Caravaggio. 
