Why did Vader allow Admiral Piet to view him (back of his head anyway) maskless?

I always wondered that. In ESB he has his meditatin chambers open just a tad....while his helmet is off...for what purpose anyway?
It allowed one of his men to view him for that brief moment.

 

The idea of the scene was not to show an officer the back of his head. It was intended to show the audience the back of his head. They did that to show "Hey, Vader IS human."

 

There's also the psychological factor. If the back of his head is gross and makes senior officers' stomachs turn somersaults, it adds to his edginess as they imagine what the FRONT might look like.

 

Maybe he didn't care.

 

Does anyone have a pic of that part

 

[image=http://i3.photobucket.com/albums/y64/tongorad/dvhead01.jpg]

Praji delivers.

 

He's got a special soft spot for Piett, like most of us...

 

Apart from the "Audience seeing Vaders skull" for story purposes(which I totally accept), it always came across as a moment where Vader was caught off-guard and wouldn't be something he would be in a habit of doing.

Vader in his suit with his choking fetish was more than scary enough to motivate Imperial Troops.

Though maybe that was Vader referring to in ROTJ when he said of the DS2 construction work:
"Perhaps I can find new ways to motivate them."

Take off the helmet and freak them out till they rush back to work rather than see the freakzoid face of Vader...

 

What if it was a blooper of Vaders'?

That would be REAL scary for Piett >)