I believe that ハード面 means that the hardware's side. (面 = side)
It's a metaphoric way of expression, like when you are talking about there are two categories of things; hardware and software - it applies to human being as well, hardware here means materialistic things such as presents, special make-up, dress, etc. while ソフト面 (software) would mean something mental (like special approach to one's boyfriend or boyfriend-to-be or partner).
Women need to get prepared for the special occasion such as Valentine's Day, both mentally and physically, to make it very romantic and pleasant.
Hope this explanation makes sense.