its like those accodian handheld fans. with the end of it in your armpit and one side attached to the dress and the other to the sleeve so when the arm goes up, the fan opens
When I first heard your description I thought of something like this which I would consider a pleated kaftan, but I don't know if this is what you meant -Click-
They seem to be starter horses, but why are they all also fewspots? None of the other appy patterns. Looks like they pass the frame onto their offspring, which do have other patterns.