Milk-bottle shoulders

Jack Malvern, writing in The Times, describes as ‘a woman with milk-bottle shoulders’ Olivia Boteler Porter, the subject of a portrait held in the Bowes Museum in Durham now said to be by Van Dyck.

Milk-bottle shoulders as a term used to describe sloping shoulders does not seem to be in widespread use at all – not in the OED & Google turned up only one result.

Links
How a lady came out of the closet
Van Dyck portrait spotted online
Related posts
Sloping shoulders