This is an example of a bad photo as the lighting is coming from the wrong direct and is not directly on the models face. The model has no direct eye contact with the camera so this will not visually connect to the audience.
This is an example of a good photo as the picture is not dull and there is no shadows upon the models face or body. The model is also giving the audience direct eye contact and she would be easy to cut out as the colours she is wearing contrast from the background in the photo.
These photos are both my own photography, and taken myself.