Reply #11: Weiner was just joking around.

[JDPriestly]

Rep. Anthony Weiner showed an understanding of the new age of privacy during a press conference on Weinergate this afternoon. Weiner subjected himself to a half-hour whacking by journalists, during which he admitted to lying about his Twitter account being hacked, saying that he did send a photo of his little member of Congress to a Seattle college student “as a joke.” He had intended to send it privately as a direct message, but messed up. On Twitter, this is called a “#DM Fail.” It happens fairly often — it’s the equivalent of the inadvertent “Reply All” of email — and is a good reason NOT to use Twitter as a forum for sending racy photos of yourself.

http://blogs.forbes.com/kashmirhill/2011/06/06/anthony-weiner-comes-clean-about-dirty-photos-and-phone-calls/

That would explain this. After all, the picture is about at the level of a 10-year-old's humor. It is juvenile and silly, anything but erotic.