Allegorically tells how something is said or shown: in the manner of an allegory, so the surface events point to ideas or a moral lesson. A writer may speak allegorically about war by writing about a storm. It is an adverb of method, not a name for the story itself. You will mostly meet it in essays and criticism; ordinary talk just says 'it's really about…' Though actually, some people use it as a fancy twin of 'metaphorically.' Stricter use keeps it for a whole designed second story, not one comparison.