That dress is amazing! But I think my favorite part might be that the girl isn't a "typical" swan-maiden (blonde hair and fair skin, huge blue eyes that sparkle in the moonlight...) I'm also extremely curious about what she's looking at.
I definitely see where the Disney inspired art style is.
The reason I like this piece is that the woman's beauty and elegance is understated in the gown's simplicity and the lack of overly ornate jewelry upon her body. Add to this the fact that the dress is asymmetric with the feather design sweeping to her left makes this piece very interesting and engaging. I've seen other gowns drawn by other artists in varying styles; very few of them have managed to capture high elegance as much as your design.
Continue drawing and finding inspiration where ever you may stumble upon it (or it clubs you with a Trans-Dimensional Hammer).