The term "white knight" has been well documented in places such as Wikipedia or various online dictionaries. But none of those definitions seem to encapsulate the meaning from this quote:
[White knights] are renowned for beating around the bush and not saying what they actually think instead they cover their real thoughts with stupid compliments. [White knights] also notice things that your typical man would not (see below)
Typical white knightish sentence to a girl: You look fantastic did you get your hair done?
Typical non white knightish sentence to a girl: I'm hungry/horny
The above portion has a handful of various grammatical oddities but their use of White Knight does not fit the definition from the dictionary:
a hero who comes to the rescue.
a beleaguered champion who fights for a cause.
a company that comes to the rescue of another, as to prevent a takeover.
What does noticing new hairdos have to do with rescuing people?