Please read the following passage (not by me) before you attempt to answer my question.
my advice this morning to a LJ friend who can't decide whether to move in with his sister and her sprog, or with an aquaintance of his who has a bit of a drug issue:when you live with someone, you are exposed to an entirely different side of that person. All their weaknesses, bad habits, and "quirks" come out. For people who are slaves to some kind of all-consuming obsession (that becomes a endless money pit), their judgement becomes warped. Things you and I, or any reasonably sane person would consider impossible behavior - stealing from family and friends, cutting off contact with those who don't share their indulgence, are all perfectly OK behaviors. Their obsession rules out all other attachments, all logic, all basic civility. They will do anything to get money to feed the beast, and woe to anyone who dares criticize their decision.
Then there's your friend with the cocaine problem. I can't recommend living with him, either."
Basically, the writer is going to great lengths to describe one of the potential roommates and make the reader think s/he is describing the cocaine addict, only to surprise you with the last line. What is the name of the literary device the writer is using?