Based on the failed pilot (now on myspace) "Gay Robot", it is similar in meaning to the term "No Homo." It can be used to note that something you're saying sounds gay, but you don't mean it in the gay sense. It can be used before or after your statement.
Also, if you fail to flag your homo sounding comment with no robot, someone can call no robot on you, just as with no homo. The phrase no robot is convenient when in a public place because it is not as offensive as saying no homo in a crowded place.

A man who messes around with other men, but no one would ever know by looking or talking to him. Used by gay black men to identify masculine gay men or DL Brothas.