There was a discussion in this subreddit about a month ago about this spam.

Here's one of the top-voted comments from that thread (by /u/gravyfish):

I think MYGODWHATHAVEIDONE is correct:

"Exact same type of spam was on 4chan's /b/ and /r9k/ a couple years ago. Just a racist troll."

But I will elaborate: Since the beginning of /r9k/'s descent into a cesspool of trolls and whining, men with East Asian physical characteristics have often been discussed and viewed as being the "low men on the totem pole," essentially the lowest in the fucked-up hierarchy of male attractiveness that has long-since held as canon there. Trolls capitalized on this by posting pictures of Asian guys with attractive white women, ostensibly dating or in some sort of romantic relationship based on their body language and proximity in the posted photo. This, of course, was intentionally designed to anger /r9k/ readers, as it was intended to show the single/virgin users that they were actually at the bottom of the social ladder, because if even the gentlemen in the pictures could find attractive white women to date, the /r9k/ users must simply be socially inept, unattractive, etc. This fit in nicely with the overwhelmingly popular Alpha/Beta paradigm of male behavior that has dominated /r9k/'s thinking for a while now, as well as the the rampant and abject racism many users there exhibit. As more and more trolls began to use this sort of post to get a rise out of /r9k/ readers, it essentially became a meme, like any popular 4chan copypasta, and though it seems to have spread to reddit, the lack of established in-joke makes it irrelevant and confusing.