It's a still image, and yet...
The above image here is an example of a cinemagraph that, initially, looks like an image of a nicely composed scene: a scene from a photographer's still-life shoot. But suddenly, there is movement that makes you look again.
I don't just create a cinemagraph for the sake of the cinemagraph. The "still" image needs to be well-made and interesting. I keep in mind composition, color, lighting and all of the other elements that are important in creating a good still photograph.
I create scenes that have visual interest even without the addition of movement.