User blog comment:DancePowderer/The Smiling Man, Part 4/@comment-4889755-20140425014732

Doflamingo has basically been wearing a mask this whole time. We've seen a cocky, full of himself person who has been a step or two ahead of the game for years.

That is untill Law cut the factory. This showed Doflamingo frowning. The mask being peeled off.

Then the events after Punk Hazard and during dressrosa occured, and Doflamigo's plans kept falling through. He slowly began loosing his cool and the mask kept coming off.

Now, with his final, last ditch effort to kill the Heart-Straw Hat alliance plus the Dressrosa rebels has been initiated, the mask his almost off. He's going literally insane, and like you said, heiritage is showing.

I predict that, when the mask is fully removed and Doffy completely loses it, the thing we've never seen him without. His glasses will be removed.