L2/R2, could they be nonsensical?

As this is maybe a first point of agreement between Fleury and myself I promised to make of it a post.
In a recent comment he wrote:

An Elasto-Plastic Model of Avian Gastrulation #3

This one is quite short but certainly the most important points. Fleury presents:
We assume that the blastodisc is a composite structure, namely a “sandwich”: Extra-Cellular Matrix/ cellular layers/Extra-Cellular Matrix. (p8, c1)
I suppose that here what is described is not the blastodisk but the epiblast. But this is not clear as there are several cellular layers. [...]