Posing can be weird
Yes, indeed! Posing can be super weird for some people (me included). Whenever I do a photoshoot, I try to make the model as comfortable as possible so they can get in the groove of posing. I also try to go along with their movement or their own poses. I like telling them the facial expression I am looking for, and just try it until I get a good pose or just a candid photo.
For posing, something else I love doing, is either saying something funny or something weird/controversial to get them to make a real facial expressial. When someone is genuine with their facial expression, the pictures have potential to come out even better than planned.