This is possibly the quintessential mid 19th century dress. In form, fabric, and decorative details it follows every dictum of its time to the letter. And it manages to do so with great grace, which is why this style, though out of fashion for over 150 years now, can still resonate, and contribute to the conversation we call Attire.
The use of box pleated trimmings was very commonplace during this time, and the repeating swags of them a common device. One of the reasons such self fabric trimmings were so popular was that it allowed the lady making it to use up all the scrap pieces from the dress cutting, lessening waste, and keeping the cost down a bit.
Wait for it, it'll be back.