A white high-slit dress has a broad folded-looking edge below the shoulders and a relatively narrow long skirt. The opening rises over one leg, while bright and shaded areas run down the pale surface. The front view helps compare an uninterrupted colour area with the more patterned bodice reference. It does not identify fibre or show the complete rear construction. Those remain questions for the actual product rather than conclusions from the smooth appearance.
Try a similar opening with normal steps, then sit and observe the coverage from the side as well as the front. Check the hem with your chosen shoes. The folded upper edge deserves its own arm movement test; its width alone cannot promise support. Put on your planned outer layer and see whether the neckline needs repositioning afterwards. If an alteration is suggested, ask how it changes the fold arrangement. This gives you a practical basis for deciding whether you want the narrow silhouette and high opening together, rather than borrowing both features simply because they look striking in a posed photograph.