That is a capitalized Platonic-ideal Curator, at the same remove from reality as “The Artist” is from any actually existing painter. My ideal curator also has a lot in common with my ideal critic. Both are broad-spectrum receivers in human form, resonating to an unusually wide range of artistic input.
More prosaically, they need to be able find the value in whatever piece of art is thrown at them, and guide their audience along the easiest route to access it themselves. They also need an unusual amount of empathy for that audience, being able to imagine what a creation will look like through other people’s eyes.
The difference is that the curator can also take more of a creative role, assembling art to match their own vision. An exhibition can be something like an essay, beating its own path through some domain. It tells some stories and ignores others, makes things look different by adjusting their context.
Any actually existing curator, though, is forced to do this within constraints of budge, institutional boundaries and the availability of works. That’s why I get so much joy out of playing fantasy curator: I ignore practical limits to design impossible shows with selections from all the collections in all the world.