I personally chose not to prepare for the HR interview before hand as it helped me be more honest the interviewer also send this and tried to neutralize the situation as I was a little nervous at the start of the interview, the interviewer tried to ease me into the process and by the end we were having a frank and friendly conversation. It was evident that the questions were devised to throw you off of any preparations done beforehand, for example there was a rapid fire sort of round in the interview with random word association exercises.