Spielberg Has Meetings In The Dark

It seems that whenever a creative meeting is about to take place about a project he's involved in, Spielberg's people alert the attendees, "By the way, he likes to take his meetings with the lights off."

It's not because he's hiding anything, lookswise, by the way; the guy looks good enough for daylight (though it's not necessarily something for ET to phone home about).

So what could be the motivation for making meetings into a sort of intellectual seance?

Maybe it makes people feel freer about exchanging ideas?

Or less self-conscious about what they're wearing?

Or maybe he wants to leave open the option of not showing up.