By 1928, such looks as this one, with its side panniers of the Robe de Style fashion, had become passe', and the sleeker, leaner looks that would dominate the 30s began to emerge. So this dress, though undeniably lovely, was an idea on its way out, already supplanted by other forms. In that, there is a subtle subtext. We are looking here, not only at a dress who's idea had already passed, but a physical symbol of a way of life that was rapidly vanishing. By the mid 1950s the official English court presentation levy would be gone, never to return.
As a final aside, to give you an idea of just how many of these things they turned out, here's another court presentation dress from the same year. This dress is also in the Met collection. There are certainly differences in the design, from one to the other, but the materials, types of techniques and decorations are the same. Organdy, chiffon, lame', ribbonwork flowers, thin metallic cord, shoulder mount train, panniers.