It emphasizes that the description just given can also apply to oneself. It is usually used to refer to a description in the previous sentences just given. I could say "I could describe myself in the same way." OR "That description could also be used for me." However, the image given, of a person describing themselves, is more dramatic and the idea more firmly set by saying it "I could (right now) be describing myself (in the same way as I've just described him/her/them)"