We can look to Clement Greenberg, who writes in parallel about art to clue us in to a tactic of Stein's project:
The limitations
that constitute the medium of painting—the flat
surface, the shape of the support, the properties
of the pigment—were treated by the old masters
as negative factors that could be acknowledged
only by implicitly or indirectly. Under Modernism
these same limitations came to be regarded as
positive factors, and were acknowledged openly.
Much as modernist painting draws attention to its insistent curiosity with a certain formal property (like color, or the flatness of canvas) to which it is bound, and that fact taken as its subject matter. In Stein's, that formal property is the functioning of grammar. Stein's writing privileges, in some sense, form over content - syntax itself is taken to be the subject matter over which Stein madly pores and iterates through; the contents of the sentences themselves suspiciously arbitrary or given to chance. The more senseless, absurd, or infantile, the greater the tension against the rationalizing power of syntax and the more heightened the poetic affect yielded.
In creating her work, Lezra claims, Stein is both offering herself as one-of-a-kind writer whilst also acknowledging that she is offering one of potentially many solutions to the task of meaning-making through writing.