The Day Plaid wrapped and pinned in Victorian era

[Tobus]

Getting the plaid to look like it's on the bias was mentioned, here it is

Hmm, he's actually wearing it opposite from the MacLeay examples. His is on the bias across the chest, with the draped portion seeming to be square (i.e. the tartan lines follow the drape). I want to do the opposite of that, as MacLeay painted: the portion across the chest having the tartan lines following the length, with the draped portion on the bias.

I'm thinking it may have to do with tucking one corner of the plaid either into an epaulet or under the rest of the plaid at the shoulder. That would get the fringe to cascade down, but it still wouldn't "turn" the tartan to a diagonal orientation. I'm stumped.