TMZ described the incident like this:
Jimmy Fallon got two big eyefuls at a signing for his new book "Thank You Notes 2," when a fake mustached fame-hungry female "fan" went topless at a Barnes and Noble in Manhattan on Thursday.
Turns out the streaker is this chick named Holly Van Voast, who has been known to get attention by flashing her lady goods in public before. Just a few months ago, the peroxide blonde was arrested for baring her knockers inside NYC's famed St. Patrick's Cathedral.
While Jimmy did seem to get a kick out of it, security promptly escorted out the buxom wonder.
Here is a video of it happening, starting around the 10:30 mark. Video is NSFW — some nudity.
And here is a video of it happening from Harvey Van Toast's point of view:
Guys, this is an "only in New York City thing." Everyone, come to New York to see this! Come on! Why are you still not in New York?