The ghost of the forest dweller haunts the simple fable of the Nyaya version of upamana. He it is who gives a name to the cow-like creature you might come across in the forest. The discovery of the denotation of the name ‘gavaya’ is what upamana is about. A contrary view is that denotation of this kind is achieved by the use of upamana but is not its sole fruit. Dharmaraja Adhvarindra of the advaitic vedanta school manages to send off our intrepid explorer without mentioning the ‘forester’. However the name ‘gavaya’ is given which seems to suggest denotation as an end point. If one omitted to mention the name and simply stuck with the core knowledge of ‘like and unlike the domestic cow’ that would be a means of knowledge. As the logical operation of the simple binary, like/unlike, it would tie in with the likewise simple switch of background/foreground of the arthapatti pramana. They both have a simple immediacy.
Another concern is the supposed use of memory when you spot the gavaya. Your memory of the cow may be operative in your judgement of likeness/unlikeness and memory is not regarded as a reliable means of knowledge. The normal counter is that likeness or unlikeness in the gavaya is a contemporary experience and therefore not a memory. I sense here a frail subtlety which is in any case not needed as having a concept does not involve the use of memory once that concept is acquired. You have the capacity to use the concept permanently present to you.
In short the restricted diet of examples of upamana may be due to seeing denotation as its exclusive fruit. Consider the duck-billed platypus:
The platypus is among nature's most unlikely animals. In fact, the first scientists to examine a specimen believed they were the victims of a hoax. The animal is best described as a hodgepodge of more familiar species: the duck (bill and webbed feet), beaver (tail), and otter (body and fur). Males are also venomous. They have sharp stingers on the heels of their rear feet and can use them to deliver a strong toxic blow to any foe.(from National Geographic: platypus
Utter unlikeness to anything ever seen before may be a means to knowledge in the sense that it mediates an expansion of knowledge.