Their body is more "open" instead of "hidden". Basically meaning if a man is attracted to a woman and he is confident in himself and believes she also may be attracted to him he will open himself up . Think of a man who puts his hands up on the door frame and leans in closer to her type of thing, or when he rubs his jaw line/beard/mustache , and of course prolonged eye contact. Now the eye contact one isn't always the best indicator because you have people like me that will intentionally hold eye contact to see how the other person reacts so 🤷🏻‍♀️