The Richard Glasstgone article on "The Influence of Cecchetti on Ashton's Work" was very helpful making in conceptualize these points. Next step -- after acquiring a concept -- is to learn how to look for and appreciate the concept in performance. Ashton has become almost invisible in U.S. ballet performance today and, I assume, in studios as well. So, of course, has Nijinska.
Ashton was influenced by the Nijinska’s use of picturesque rounded arms and non-academic epaulement together with a freedom of a flexibility of the torso. In this Les Biches was an example, whose neo-classicism undoubtedly led to Ashton's essays in this genre and is also reflected in "Les Rendevous", "Symphonic Variations", "Monotones", "Marguerite and Armand", etc,etc,etc.
[ ... ] What was obvious that both on and off-stage was that Ashton had a kind of adoring reverence in respect of Bronislava Nijinska
I have always been fascianted the expressiveness of epaulement, arms and torso. This, however, is sometimes lost or or underplayed in Balanchine-influenced choreography that I grew up on. I see that I will have to will have to start looking more closely at YouTube clips and other sources so I can get a better feel for what you are talking about. This will be a good project for the long, hot summer. As someone who's first and most important ballet experiences were Balanchine, it's fascinating to spend time looking quietly at this alternate (but not TOO alternate; I mean it's not Cambodian court dancing ) way of expressing the body's potential for beautiful movement.