I believe it is much more common for people to recall specific sounds, especially music, and to be able to imagine different sounds in different contexts, even variations on sounds you might not have heard before. For me, visualizing elephants is quite similar to imagining sound, but "weaker." So I can imagine a either a cartoon elephant on a 2D screen, or a "photorealistic"[1] 3D elephant I can rotate around, etc. It is much "fuzzier" than auditory stuff and requires more focused concentration; relatedly, I am a fairly talented guitarist but absolutely dreadful at visual art.
Another example: it was recently demonstrated that rats can use their imagination for problem solving[2]; specifically, they can visualize (or "visualize"?) the layout of a maze they've learned, thinking though what paths to take based on their memories. It seems beyond the reach of current science to answer what the rats were thinking about exactly: maybe it was pure olfactory and tactile reasoning. But whatever it was, there were clear neural correlates between those thoughts and the physical layout of the maze.
Another example I can't find the source of now: crows were trained to respond to an extremely faint pulse of light beamed onto a wall. The intent was to make the crow uncertain about whether they actually saw the pulse and monitor their brains while doing so. After the pulse was shown, the crows seemed to compare their recent sensory experience against their past memories, trying to rule out false positives. Think about doing this yourself: you might initially think you saw a pulse, compare to the memory of the last time you actually did see a pulse, and realize that the actual pulse was clearly brighter, so whatever you saw was probably either a flicker or an illusion. OTOH if whatever you saw actually was quite bright and circular, it was probably a pulse. Crows seem to have similarly advanced reasoning.
Putting these together, I am wondering if perhaps "they really see it" is a phrase whose meaning is entirely determined by the listener. Humans have impressive cognitive diversity and, just as some people are truly tone-deaf, some people have "true" aphantasia. But for many people, I wonder if the difference between "visualize a picture in your mind's eye" and "recall the visual details of this object" might largely be a difference in viewpoint and perception, rather than actual recall or reasoning ability.
[1] I do not mean that my imagination is actually true to life. Crudely, I mean that I can semi-plausibly BS details similar to an AI neural network. So I picked "lush cinematic glory" but for me "accurate shape, texture" involves a very loose definition of "accuracy." I suspect that's true for everyone that doesn't actually live and work with elephants. I don't have to BS the details of my own cats.
[2] https://www.science.org/doi/10.1126/science.adh5206