Davies and Vaughan, eds., The Republic of Plato
The date and the significance of this interesting fragment are both difficult to determine. The handwriting is earlier rather than later, but it could easily date from anytime between 1852 and 1860, though the style suggests an earlier rather than a later date. The terminus a quo would be 1852 since DGR is quoting from either the first (1852) or the second (1858) edition of Davies and Vaughan's
The Republic of Plato
(the pagination of those two editions is the same, whereas the third (1866) edition—the basis of all the later ones—is very different.
By underscoring the word “imitative” DGR is implicitly invoking a distinction between imitative and imaginary representations. The distinction goes to the core of the tension, everywhere apparent in DGR and everywhere relevant to our understanding of Pre-Raphalitism, between Ruskinian and Paterian approaches to the work. This brief note does not appear to takes sides on the matter, but simply to call attention to the distinction.
The document has never been printed.