The differentiator is whether the result is worthy to look at for humans, that's all.

In case of the OP, you forget that the human had to predict that the combination of two would be interesting for other humans, and then construct the prompt, possibly selecting the best pictures. That's who did most of the work here, and it was effortless for the neural network of a human. Could DALL-E analyze the world autonomously without human intervention at all? No, it's an open loop system.

Novelty hinges on the ability to conceptualize things, not the execution. Sure, DALL-E 2 shows a glimpse of conceptualization internally as it works with compressed descriptions (concepts, abstractions) of things it draws. But it's super limited and not flexible enough to create new ideas, it doesn't have either short-term or long-term memory, it doesn't change, it has all knowledge about Kermit and Blade Runner pre-baked, and so on. You have to re-train it from scratch every time you want it to remember something truly new, there's no feedback loop to do that. Human ability is still much more powerful.

DALL-E 2 is almost at the point where it can supplement the human conceptualization with AI execution, though. Possibly in a couple iterations it will be there, with more believable results. In very limited cases, of course - as it's temporally unstable (it makes a totally new image each time), cannot correct the output from new details provided by a human (like a professional concept artist could), etc.