Photography has been and hopefully remain as much about playing and experimenting. One of such fun things is to introduce an artificial light sources in a landscape. The official term for it is “light painting” but for me it is just playing with flashlights, imagining what a landscape can be, and then getting a surprising result.
Like in this photo that I took at the Second Beach in Olympic National Park just after sunset, when it was dark enough for a long exposure and dark enough for a flash light (actually 3 flashlights) to make a difference.