It is turning people against each other, with the good and bad in people split off and unintegrated, then projected onto someone else. The person sees “all-good” and “all-bad” in others, with no room for ambiguity and ambivalence.
Films depicting a character with Borderline Personality Disorder, such as Wicker Park, and Rose Byrne’s character who purposely causes a rift between Josh Hartnett’s Matt character and Diane Kruger’s Lisa is showing us splitting at its most definitive. When "splitting" is combined with "projecting", the undesirable qualities that one unconsciously perceives oneself as possessing, one consciously attributes to another.
This is a very bad thing to encounter in a date, and they are not going to be a candidate as a mate anytime soon, either.
It’s subtle when you encounter it, because the person might not begin the interaction by describing you in derogatory terms. Instead, you may find yourself feeling very uncomfortable with praise that is being heaped on you. One would think this to be an enjoyable thing, but it is not. There is an ungenuine spirit to the person’s admiration of you, which is in part because you are likely picking up on their focus on how similar they are to you in all your glory.
One can tell how artificial the words of praise are, and how it is that it is very likely in the near future that they actually spill to the opposite in their opinion of you. You can feel it in your bones that they will be just as quick to hate you for the same lack of reason with which they had been praising you a moment ago. Which makes it all the more likely that they will shift views of you, and tarnish your reputation, if not your deepest sense of self and identity. The good and bad in the person have been projected out onto you and others, so that the original person may continue to go about surviving the conflict, and stable.