It probably helps that Norrell does not, in fact, have any idea what is in fashion or not. He assumes it probably is.

He picks up a bell and rings impatiently for attention, determined now to save Elizabeth from her perceived fate of probable starvation.

"You cannot be expected to concentrate on studies, on practice or much of anything else if you have not eaten properly!" he exclaims, "it is no wonder you find yourself struggling! No, no, we will find you something -- it is a wonder you have not fainted clean away!"