Fatal Online Dating Errors - Mistakes that Men Make

Saw this on Yahoo! about top 10 mistakes that men make when responding to online personals or trying to contact women online.

One of them definitely happened to me:
"Don't ask her if she wants to have sex with you on the second email exchange, and don't send her dirty pictures of you. Women are all about connecting with their minds. Just because you're looking for a quick fling, that doesn't mean she's going to respond."

For some reason, (some) guys thought that women would be more interested in them if they sent them pictures of themselves below the waist. What's the logic behind that?