I think the effect of the light on the face when taking pictures is really important! what do you think?

Of course it matters. You probably didn't use the flash when you took the picture, did you? I feel that the photos you take may be that the light on one side is weak and the light on the other side is strong, so it will appear very layered and three-dimensional. Photography is painting with light, and light has a great influence on the quality of photos. As for how to use it, I suggest that if you like photography, you can take more photos (using ordinary camera film is expensive). In addition, there are many articles about it on the Internet. If you don't like it, you can learn about it.