This is very simple unposed shot, with no light added by me. The light is all what was already present in the scene.
Some people call that “natural light” but actually the main light here is an artificial light source. Note, too, I say “main light” because there are two light sources.
Some say “available light” but arguably I had a bunch of flashes and an LED light available to me, had I wanted to or needed to light the scene.
I call this light ambient light. And even though in some ways you might say “it is what it is”, there are still choices to be made to work with it – in terms of exposure, white balance, composition – but beyond this one photo, you can learn a lot about light by looking at a scene like this.
For instance look at the colour of the light in the bathroom, and the colour of the light in the bedroom (the other light source is cloudy daylight from the windows behind me).
Look at the quantity of light in the two rooms. The bedroom is barely lit, but it’s important to the shot that some of the light there registers. Otherwise I end up with just some negative space.
Look at the quality of the light and how that bare bulb light source above the mirror in front of the groom throws light around the space.
And look at the direction, which you can infer from any shadows.
Learning to see light like this, and analyse it, even if it’s light that’s already there (actually, especially if it is) is the single best way to learn to add your own light when you need to do that. If I wanted to emulate the light on the a subject’s face in some future photo, I just have to remember this photo and the relative positions of the groom and the light over the mirror and I’ll get pretty close to without too much tinkering with the use of one added light source..
That’s why, if you want to learn how to light a scene, analysing simple everyday scenes like this is a good thing to do..