Once you introduce yourself to a girl your body language should become more relaxed. In FIRST PHASE situations you had to assert yourself to make your introduction, and that required the positive body language described earlier.

Now in the SECOND PHASE you will be acting more casually and engaging in small talk while you are starting to get to know her. You don't need to be facing her squarely, looking directly at her as much, or standing so close. You are now trying to put her more at ease.

Then, as you get to know her better, and at times talk of more personal things, you will intensify your body language again by more direct facing, closer proximity, more eye contact, etc., during those times.

Just as your conversation should alternate between periods of more intense personal discussion and more relaxed small talk, jokes, etc., your body language should also vary accordingly.