A response when there is no comeback to a putdown. Derives from a person sticking his middle finger up at somebody, and using his other hand he points at the middle finger in a demonstrative manner, and says You, this. Example: Sally said to Bobby, Your breath stinks. To which Bobby replied, You, this.
YOU, THIS
Meaning of YOU, THIS in English
Slang English vocab. Английский сленговый словарь. 2012