The navy outlined bodice is the clearest feature in this view, but it is not the only relevant one. Dark lines frame a pale upper section and continue over a very broad skirt. The leg opening reveals the shoe in the arranged stance. For a wedding guest, the pale backing and expansive shape deserve as much attention as the navy surface lines.
Compare the dress from a normal standing distance before deciding that the dark colour makes it a quiet option. If the hosts’ bridal direction is unknown, a full pale-backed skirt is a reason to ask a concrete question about the complete design. A small dark bag would add contrast but would not remove the volume or change the neckline.
At the fitting, walk through a doorway and sit without lifting the skirt into a photographic arrangement. Check how much space the hem needs beside a chair. A ceremony jacket should also be tried with the dress: a short straight edge across the waist may sit differently from a wrap laid diagonally over the upper body. Choose the layer by seeing the full outfit.