[ItsOurTimeNow]

I think the green light is the Witch King's signal to Barad Dur that he has left to go to war.

Hmmm...I didn't think about that.

But it doesn't explain the two gargoyle-like statues on either side of the entranceway. I was under the impression that those were the Watchers. Could they be just the standard "decorations" of Minas Morgul?

[maquiladora]

Hmmmmm, I never considered the watchers 'till now. I always thought it was that this summary of the chapter calls:

...Then lightning erupts from the roatating Morgul-spire, and the great cry of the ever-dying Lord of the Ring-wraiths issues from the stony maw of the city gate. The War of the Ring at last begins...