Eyebrows signal our mental thoughts. The shape of the eyebrow also tells you how the person is most comfortable in framing their world. Mac Fulfer is a face reader. Round eyebrows are people whose mental focus is people-oriented. Straight eyebrows are people who need the facts.
Angled eyebrows are people who want to stay mentally in control.
You may be skeptical. But Mac Fulfer has reason to believe this works. He's a trial lawyer who learned face reading to get an edge in jury selection. One of the things that I discovered in 20 years of practicing law is the least reliable information that we ever get from people is what comes out of their mouth. So the value in this comes in being able to look at someone and know immediately OK, this person is defensive, or this person is so stubborn they're not going to change their mind.