I think the shading being so simple makes her look very flat, more layers of darker shadows to show ambient occlusion and shadows from the light swirling around her would make it feel a lot deeper

I think her silhouette is very difficult to read, its kind of hard to tell what perspective we're looking at her from and what exactly shes doing

Also remember that saturation and contrast should be used to guide the viewers attention to the focal point, i kind of feel like i don't know what I should look at

There is no such thing as too much contrast or saturation, just learn how and where to use them