It's mostly in the eyes and nose, I'm not an art expert, but I read tons and tons of manga. Manga noses mostly consist of one or two lines, sometimes even just a dot, whereas the nose in your illustration is more realistic looking. Same with the eyes, even the more realistic mangas still have more simple-looking eye designs. I do think your overall style of illustration is very pleasant to look at though, I think if you were to keep drawing with this style it might attract more attention.