Mismatching Metaprogram

About: relationship filter – sameness and difference | nlp mentor

I have never understood a mismatching strategy for relating to the World.  A mismatching strategy examines all the things something is not & throws them away .  When that process is finished & there is no more to throw away then the mismatcher assumes he can finally relate to it.
It gets really complex when the ego is involved & the "not me" invoked.  What does he throw away?