Please help--What is the difference between an unstructured drape and a structured one?

It came up in this thread by Marlene.

It has come up before, too and I am just not sure what we're talking about.

She identifies one sort of topper as a "drapey cardigan." All that comes to mind for me is a waterfall collar.

Is that #1, the one from old Navy?

Then she mentions she likes drape--but architectural drape. Is that #2, the Jones New York?

Is it just the difference in the collar or is it more subtle than that?

Thanks.