What blinks in the "Game of Thrones" intro?

It's a lens, clicking into place. As each lens is progressively added, we're able to view the cities in more detail.

I've also found this interview with one of the original 3D artists for GoT.

Interviewer : At some point in the intro, the camera is enveloped by some blades that flash for a second and make a metalic sound. What's going on there?

PH : This is supposed to be like a camera lens change. Imagine a contraption on the camera that has 3 different different lenses attached to it, and it flips so the next lens is in front of the camera.

There is a fan theory about the blink. When Samwell Tarly met the Maester at the entrance to the Library in Oldtown, the Maester was wearing a set of lenses on his eyes.

The theory is that a Maester of Oldtown is looking at a map of Westeros. And high above him in the library is an astrolabe identical to the one in the opening credits. (Minus the bright "sun" in the middle.)

The blink occurs when the Maester swaps out one lens with another.

This also fits nicely with the fan theory that the entire saga is being told/wrote by a survivor of the stories, none other than Samwell Tarly. The whole saga is told as "a song of ice and fire".

After the Season 6 Finale we also see that the orbs and rings we see in the opening are most likely an astrolabe (aka armillary sphere, armilla, or armil).

We see the same object hanging in the Citadel at Oldtown. This can be determined by seeing the same markings on the rings.

The meaning of this is still not fully known, but there is an interesting fan theory...

"The overarching saga is called A Song Of Ice And Fire after all, and in the world of Game of Thrones songs are used to pass on heroic stories and legends. So does that mean somebody is telling this story of Dany, Jon, Arya, Cersei, and the rest to future generations?"

"If that’s how it ends, some fans might be mad about the set up of the story. But if this theory is right, does it make sense for Sam to be the one that devotes his life to passing along the heroism and cruelty of everyone in Westeros? Or could it be Sam’s son who was told the story by his father and then passes it on to his own children? If this theory is accurate, there are any number of options that would make sense. But for now it is just another theory."

As for the "blinking effect" the fan theory is that this is literally a person blinking because that person is using the optical device we see the Maester at Oldtown using.

Opening astrolabe

Citadel astroslabe

_{Answer originally posted on M&TV}