In the introduction to The Hunting of the Snark (Penguin Classics edition, 1962, 1974,p. 17), Martin Gardener wrote:
How well the academician Holiday succeeded in producing grotesques for the Snark (it is the only work of Carroll’s that he illustrated) is open to debate. Ruskin was certainly right in thinking him inferior to Tenniel. His drawings are, of course, thoroughly realistic except for the overzize heads and the slightly surrealist quality that derives less from the artist’s imagination than from the fact that he was illustrating a surrealist poem.
I think that Gardner certainly was wrong. And Ruskin certainly was wrong as well. But, of course, that is open to debate.