Could you elaborate more on that, please?
De nada... it is one of my favourite places to spend some time.
To elaborate on the dangers of confusion? Well, it is rather easy, as with your spider, to think that since the same components are involved in the picture, that it will be so similar to all the others that it will be unable to offer anything new - a cliché.
But, not all pictures that consist of roughly the same elements are going to be virtual copies of each other - they might be of the same genre
but could still retain sufficient individuality to retain identity; thus, I think of fashion pictures against a white/grey roll of paper as being reasonably good examples of perhaps both cliché and genre. Genre, unmistakably, because they share the common location of a roll of paper; cliché if they bring nothing new
to the experience in front of the reader but not cliché if they still manage to surprise.
However, even that isn't as tight or binding a definition as might be desired - the cliché might exist even when the same idea is only seen twice. There is a famous topless photograph of Janet Jackson with her arms up in the air and a pair of male hands holding her breasts from behind, which I think was shot for Rolling Stone, but I might be mistaken. I have seen one more picture copying that pose and instantly, for me, it became cliché, even with just a single predecessor.
Maybe the problem is language or the belief that it can define everything that humans can feel. And I don't mean Janet Jackson.