It was the 'sort of' that I thought about later. There was absolutely nothing wrong with that person's assessment of the book. She felt it was fantasy, but not quite. I never got a chance to pursue that idea with her, but it got me thinking about how different readers focus on different aspects of a book. Some people have read Shards of History and labeled it straight fantasy. I've also heard historical fiction, social sf, and even hard sf/fantasy mash-up.
I just finished reading Let's Pretend This Never Happened (A Mostly True Memoir). As the title suggests, it's a memoir. But it's also a comedy. And sometimes while reading it, I thought, "No way this ever happened. This must be fiction." But then I realized the author grew up in a tiny town in west Texas, and I totally believed even the craziest stuff because that's how West Texas is. If you asked everybody who read the book how they'd classify it, some would call it a memoir, and others would label it a comedy. How do people choose one over the other? And why does it matter?
Book labels are for marketing, and marketing is meant to make it as easy as possible for readers to find it. Some books can be promoted as paranormal with a romantic twist for one group, and a romance with a paranormal twist for another. Ultimately, I think it's good to know every possible interested group to whom you could market your book. And, it helps to understand what people think of when you tell them your book is 'fantasy.' Some people will think of elves, others will think of young wizards, and still others will think of demons or vampires. This is why it's good to be able to tell people, "This book is like (insert another book/series here)."