AP Photo A new book by Wired's Steven Levy claims Zuckerberg is obsessed with his public image and that a Facebook employee blow dried his sweaty armpits before big events, according to a review of the book by by Bloomberg's Austin Carr. Facebook COO Sheryl Sandberg is also reportedly depicted as controlling of her public image. Twitter CEO Jack Dorsey responded to the story by offering to provide blow-drying services to his company's communications team. There's historical context to support the notion that Zuckerberg sweats under pressure: Back in 2010, he visibly sweated in an on-stage interview with tech journalist Kara Swisher. Visit Business Insider's homepage for more stories. Members of Facebook's communications team reportedly blow-dry Mark Zuckerberg's armpits before big speeches to get rid of his anxiety-induced sweat.