The chemise silhouette still emphasized the waist, but a waist unfettered by corsets. This more comfortable style required less courtier dressing time, and was favored by the young queen as she enjoyed the outdoors with her children at Petit Trianon.
The chemise was also less forgiving. Because it reflected the new taste for all things "natural" inspired by Jean-Jacques Rousseau, it was especially attractive to and on slim young women like Marie Antoinette. This was perhaps the beginning of youth-directed fashion.
The lack of formality of the chemise (and the fact that Marie Antoinette posed in hers for a portrait by her official painter, Elisabeth Vigée-Lebrun, who then exhibited it at a widely-attended exhibition in Paris in 1783) caused a huge scandal. The Queen, it was said, had posed in her underwear.
While we (and Marie Antoinette) may see in this style a welcome freeing of the body from the constraints of the corset, the public display of the natural body of the Queen through the thin fabric of the chemise was interpreted by her detractors as an outrageous affront to modesty and to the very dignity of the monarchy.
Whereas we may see sweetness and innocence in the portrait of the queen in a simple dress with a single rose in her hand, others saw indecency and immorality. To make matters worse, the Queen's championing of cotton muslin was also interpreted as a rejection of French silks for the products of France's imperial rival, Britain, which was flooding the market with the newly fashionable fabric from its colonies on the Indian subcontinent.