How did this get in??

I'd guess it's one of two things, either Seth the agent was testing how to use SE and to see how a listing looked or someone Seth pissed off pulled a "for a good time call" on the bathroom wall.
I might be inclined to dismiss option 2 as I cant believe it's so easy to pose and post as another agent on SE, but CitiHab is very rental oriented so it's possible.
Of course third, it may have been an SE glitch.

Senior Managing Director: Top Grossing Office 2010

Seth Hirschhorn is a marketing expert and market-savvy professional who is Senior Managing Director of more than 200 sales and rental agents at three of Citi Habitats’ thriving offices: the flagship Relocation and Sales Headquarters, fifth floor at the corporate office, and East Village office. Throughout his tenure at Citi Habitats, he has managed many offices for the firm, creating a winning sales culture. Seth’s inspirational leadership, unique open-door management style, intensive in-house training and extensive knowledge of New York residential real estate have boosted sales revenue at every branch he’s run. Once a top sales agent himself, he has played an integral role in the firm’s overall record-breaking sales growth to date.

GO SETH!

If enough of these get posted, then they will not be considered outliers. Depending on the outlier logic, these listings could at least increase the range of the upper limit. SE will start reporting 2BR at $12,540/sqft instead of $1,254/sqft.

$99,999,999
123 Anywhere #6B in Manhattan
Condo
Manhattan
2 beds
2 baths
Common Charges: $2,200

Something tells me that even though this apartment doesn't actually exist, inododo could rent it for $4-5K/month.