Mark Zuckerberg is known for arriving late for a meeting with prospective investor Sequoia Capital and giving a less-than-serious pitch while wearing pyjamas.
Now, as Facebook prepares its initial public offering, Zuckerberg's wardrobe has not received much of an upgrade.
Wearing a hoodie to a meeting in New York on Tuesday with potential investors is a sign of Zuckerberg's lack of seriousness, according to Michael Pachter, an analyst for Wedbush Securities.
"He's showing investors he doesn't care that much, he's going to be him," Pachter said. "I think that's a mark of immaturity. I think that he has to realise he's bringing investors in as a new constituency right now, and I think he's got to show them the respect that they deserve because he's asking them for their money."
Pachter said Zuckerberg was similar to Steve Jobs, the late Apple co-founder, in that he was an eccentric leader who did not want to answer to anybody.
He said Zuckerberg was "well-suited to be the chief product officer, the chief user-experience officer, to manage the design of the user interface, to decide every feature that goes in".
As for running a corporation and answering to shareholders, Pachter was not so sure.
Still, he was the first analyst to give the company a buy rating last week, even though he does not expect Facebook to experience rapid growth in revenue for a few years.
Zuckerberg has forgone his casual attire for certain events.
For example, in meetings with President Barack Obama, he has worn button-down shirts, sports jackets and ties.
Even then, Zuckerberg complemented the attire with jeans and sneakers.