I actually don't think it would be obvious. By not explicitly saying Indiana Jones when so obviously describing Indiana Jones, there is an implication present. But I think many human artists would probably ask you, "Wait, so Indiana Jones, or are you looking for something different," before immediately diving in.
Because it wasn't prompted to? Have you not ever used ChatGPT?
This seems pretty easy to test - can we just change the prompt to specifically exclude Indiana Jones?
Late reply but I did test this and I think the results show at least some originality when explicitly directed to not copy existing characters such as Indiana Jones[1] and the Predator[2]. Some elements of the original characters creep in, the archaeologist is wearing a fedora and the distinctly more skeletal bounty hunter appears to have a few dreads despite otherwise being bald, but they are distinct.
I‘m not so sure, unless you are playing a game of “name the character” you generally don‘t want Indiana Jones unless you explicitly mention Indiana Jones. Indiana Jones is a well known character, if you want a picture of Indiana Jones it is simple enough to just say: “Draw me a picture of Indiana Jones”. The fact that they didn’t say that, most likely means they don‘t want that.