At least, that's how I saw her. I'm not sure where it comes from, but I always imagine that Thingol spent every moment until his death in a bit of a trance, and that's where the original "dreamy" state of some Elves (Galadriel XD) comes from, because they were inspired by him. Not to say he wouldn't have fallen in love with Melian and she kept him under a spell against his will, but I think her power and love were so overwhelming even for a firstborn Elf that Thingol never really "recovered" from it. So I think for a newcomer wandering into Doriath and being brought before the king and queen, he would seem vague and aloof, with Melian doing all the talking. If I had to visualize it in a film, I'd give Thingol grey eyes upon first awakening and travelling, then upon meeting Melian they'd become starry and bluer, a sort of "enchanted" look, and during his death they would fade back to their original colour (albeit brightened by the Silmaril.) Point being, I think Melian is very much in charge of kindling that relationship. A very ...active woman.