they are simply indicators and the "interpretation" can vary from good to bad shrinks and other aiders and abettors. Take a person who has a set of lips that look like a mepps number 7 treble hook and lure would not be out of place and say " I bet you are a pisces" 8 out of ten times you would be right. Its not science, its observation of comparisons over the centuries. Some are better at it than others. I do not claim to know astrology but fish lips are fish lips.
regards,
daemon