Classic
A classic portrait is a picture of a person.
This is a picture of a student in Lincoln. I like this picture because of the student's facial expression. I did not edit the photo. I thought about editing it to bring out the colors more, but I decided that as school is a rather drab location I should leave the colors slightly muted to mirror the setting's true colors.
This is a picture of one of my friends in a parking garage. I like this picture because of the difference between the right and left sides of the picture. The darkness and light make the picture very asymmetrical.
Environmental
An environmental portrait is one taken in the subject's environment. These pictures show something about the subject's personality.
This is a picture of my dog in my backyard. I arranged my dog's favorite toys around him to show aspects of his personality. I edited this picture to make the colors darker. I did this to draw attention to the subject of the picture, my dog.