In these photos, one can see that the voluminous drape of the skirt is not created with pleats but with insanely full and tight gathering of fabric which would be nearly impossible to recreate in a small scale. The waist drops to a V in the front and the bodice is very low cut.
There is no opening in the fabric at the front of the skirt as there seems to be on Tonner's gown.
Here is Tonner's gown with the two areas of concern. In order to create the fullness of panniers, their pattern maker created a seam with pleats. I think it looks awful. The other area is the flap at the front of the gown.
I realize that production must take into mind costs of construction and the scale but I would have preferred some other solution.
Do you think the photographer was inspired by the photograph below to have the doll holding her skirts up?
For more information on Outlander's costume designer, Terry Dresbach and Season 2's inspiration, read this article from Vanity Fair: