This is a kind of image that I've seen in dictionaries and encyclopaedias since my childhood. That kind of educative images have a theme. In the image there's a lot of different things related to that theme but in a context. I mean, let's suppose it is an image about animals, there are not just isolated images of animals against a backdrop like this one:
This is not what I mean
... but instead the animals would be depicted in a context as if you were lucky enough to, by chance, meet all kinds of animals in the same picture frame while they were going about their lives, like this:
This is what I mean:
Here's another example about a complete different theme, notice how every geographic feature is depicted in context as if happening in an imaginary place where everything happens at the same time for ilustrative purposes:
This is also what I mean:
Often every object in the image would have a number referring to a legend under the image.
A word that occurs to me is diorama but I'm sure that's not the correct word. I don't even know what to call it in my native tongue, so I cannot do a dictionary lookup.