I think this is a necessary setting - for example, if a store owner has a bunch of images uploaded to their slideshow but isn't ready to display them (maybe for an upcoming promotion), they can get a preview for how their slideshow will look and experiment with different images and design. Or, if they're in the process of gathering images for a slideshow but don't yet have everything available, and need to wait until they have final images to display it.

It's also proving to be useful right now in our testdriveluna store, where images have been uploaded but we're waiting a couple days before the feature is live to enable the slideshow and showcase the feature.