Separates
She said, quite early on, that she did not want a dress she would keep in a bag. Two pieces is the honest answer to that.
The skirt is taffeta, gathered onto a stay tape so the fullness sits where it should and nowhere else, and it has been out twice since the wedding. The top is crepe, boned lightly, and cut short enough that the waist seam of the skirt is the waist of the whole look.
Together they read as one thing. Apart they read as two good things.