Light and shadows?

I say this with a question mark, because when my assignment was handed to me, I never really understood what I was suppose to take pictures of. :/ I guess good examples of light and shadows. But what really is that? I know it when I see it, because some photos the only 'important' part is the shadows it creates, but how to capture that in a camera is confusing. I think mostly I just took pictures of painting/windows/and mirrors with interesting light in the background.

                                       Here's a picture of a painting that is in my living room. It's a picture of a deer out in the middle of the woods with snow, pine trees and a small creek. I like this photo because in the middle of the photo there's a door (reflection) like it's saying enter into this world.

                                            Here's another painting and reflection of light. See I can improvise. I paintied this painting FYI, but you can't really see it that well. Instead you can see the old lamp sitting in my living room and the end table. I had to increase light and contrast to make it show up better, else it looked like a giant undefined blob.

                               What do ya' know? It's another painting reflection! :O How unusually. Boy I'm on a role going around taking pictures of painting in my house and looking for interesting lighting backgrounds. I also painted this one too. I think this one is my favorite (reflection/picture wise -not over all painting) It's kinda random, a nice abstract red and purple background meshed toeghter with my kitchen dinner area.

                               Hmmm, one without a painting, how unusual. I figured that I should show at least  one photo without a painting in it. here's just the living room without much lights on, and just the sol living room lamp is standing there. I tried editing it by increasing the contrast and light exposure to see what it shows, and it looks really creepy. The little black spot on the right looks like a man in a black trench coat, how unusual!

Not much to say about this one, but it's amazing on how dirty and gross mirrors look when you put flash on them. Think I should clean it?