What does "a paradox wrapped in an oxymoron smothered in contradictions in terms" mean?
A witty attempt to portray her as more than meets the eye, that there are things about her that you wouldn't expect just by looking at her.
Apparently, this is a quote taken from the show NCIS and is said by one agent while under truth serum about another agent. The full quote is:
Abby Sciuto. Resident NCIS Forensic Specialist, heart and soul. A paradox wrapped in an oxymoron, smothered in contradiction. Sleeps in a coffin. Really the happiest Goth you'll ever meet.
There are two things going on in this quote - the first is that the character who said the quote, Special Agent Anthony DiNozzo, is trying to explain how he views the Forensic Specialist Abby Sciuto, who while Goth is also a quite energetic employee (Goths having a reputation for being dark and gloomy and not seeing the point of doing things (NOTE - for anyone who is offended by this remark, please know it is my ignorance you are reading, not my prejudice)). So there's a witty attempt to portray her as more than meets the eye, that there are things about her that you wouldn't expect just by looking at her.
The second thing going on is that the quote is based on another, more famous one. In WW2 (1939 to be exact), Sir Winston Churchill gave a radio address in which he talks about the anticipated actions of Russia - what it would do in terms of Nazi aggression and the like, and he said:
"I cannot forecast to you the action of Russia. It is a riddle, wrapped in a mystery, inside an enigma; but perhaps there is a key. That key is Russian national interest."
This one is more about the fact that Russian actions couldn't be easily guessed but that perhaps one could attempt to view things from the point of view of Russia itself and make an educated guess that way.