There's a quote that goes something like "good artists borrow, great artists steal." A quote investigator post looked into this and found a similar quote in a T.S. Elliot essay from "The Sacred Wood: Essays on Poetry and Criticism."
One of the surest of tests is the way in which a poet borrows. Immature poets imitate; mature poets steal; bad poets deface what they take, and good poets make it into something better, or at least something different.
He elaborates that:
The good poet welds his theft into a whole of feeling which is unique, utterly different from that from which it was torn; the bad poet throws it into something which has no cohesion. A good poet will usually borrow from authors remote in time, or alien in language, or diverse in interest.
This reminds me of art as conversation. The author's note/afterword to Too Like the Lightning describes it as a contribution to a conversation, and I'd agree. But it makes me wonder: What about it makes it a contribution? What even puts it in the same conversation? Too Like the Lightning positions itself in a conversation by directly referencing the philosophers and ideas it is in conversation with. But what about other stories that are less explicit?
Take for example the stereotypical fantasy story, let's call it "King of the Amulets" that copies tropes from Lord of the Rings and Dungeons and Dragons. Is it fair to say such a story is in conversation with Lord of the Rings? On the level of tropes, sure—it borrows the tropes. On the level of ideas, it's less clear. Lord of the Rings is more than a bag of tropes—it's also a story about the world. That's the level of ideas.
To be in conversation with Lord of the Rings on the level of ideas, "King of the Amulets" has to reference it somehow. It can do that more explicitly or less explicitly.
On the explicit side, Too Like the Lightning calls out all the references it's making. It references Voltaire, Aristotle, Marquis de Sade, Jean-Jacques Rousseau, and so on by name and by title. It provides some context about most of those references and how it relates to them. For example, there are conversations toward the end of the book explicitly referencing pieces of de Sade's writing and commenting on it that way.
On less explicit side, The Dark Tower (as far as I've read — up through The Waste Lands) makes and calls out a lot of references, but it doesn't spell out its relationship to what it references in the same way that Too Like the Lightning does. Stephen King doesn't stop to explain to us what the lines he's borrowing meant in their original context and how that relates to what he's doing in his writing. He just makes the references, sometimes calls them out through one of his characters, and then moves on. Some of them come up multiple times. "I will show you fear in a handful of dust" is referenced at least twice in The Waste Lands, and maybe more.
(Of course, Too Like the Lightning also relies in its worldbuilding on ideas it doesn't explicitly reference or spell out, so this is not to say it doesn't use that style of worldbuilding.)
In theory, one could build on a story by referencing it without calling attention to the reference. I'm sure I've seen this before, but it's hard to think of examples. When I think of indirect references in stories, the examples that come mind are on the level of tropes more than ideas. For example, in The Dark Tower, Stephen King references several times a company in his universe called North Central Positronics. The hosts of Kingslingers pointed out in one episode that the term "positronics" comes from earlier science fiction—from Asimov's writing, I think, if not the earlier play about robots, Rossum's Universal Robots, by Karel Čapek. It's first mentioned in book one, The Gunslinger, possibly a second time in book two, Drawing of the Three, and certainly mentioned in book three, The Waste Lands. King has not called attention to the term positronics being a reference and it seems unlikely that he will.
This seems like the trickiest form to distinguish from "just the tropes, ma'am" references without direct experience of what they're referencing. I haven't read any of Asimov's stories, so I couldn't say for sure, but King's robots don't seem to comment on the Three Laws of Robotics. That means either this "positronics" reference is conversation on the trope level, or it is conversation about the themes more than the mechanics—and, not knowing the story, I don't know the themes. The more subtle the reference, the funnier it gets to call this a conversation. After all, who are you conversing with? How would they or anyone else know?
The stereotypical "King of the Amulets" is in conversation with other stories only on the level of tropes, not on the level of ideas. That's one thing that distinguishes "King of the Amulets" from a book like Too Like the Lightning. To be in conversation on the level of ideas, it would have to reference those ideas and explore, contradict, or comment on them somehow.
Conversation on the level of trope is great, but I think it's not enough for what I want to write. I've tried writing purely on that level. The result feels flat and unsatisfying. It ignores the substantive part of the stories I'm writing in conversation with. I think I want to write stories in conversation not just on the level of tropes but on on the level of ideas, too. (But in conversation with what?)