What is the nature of Tatooine's eclipse?

Question

At the beginning of his revised fourth draft of Star Wars Episode IV - A New Hope, George Lucas narrates that the planet Tatooine emerged from a total eclipse.

The awesome yellow planet of Tatooine emerges from a total eclipse, her two moons glowing against the darkness.

According to the 1977 novelization of the film Star Wars, ghostwritten by Alan Dean Foster, Tatooine circled massive G1 and G2 stars which in turn orbited a common center between them with peculiar regularity. Also, Tatooine had three moons (two depicted in A New Hope and the three in Episode II – Attack of the Clones).

I ask if there is some explanation of the nature of this eclipse in the Star Wars Canon or Legend. Is he referring to a solar eclipse that occurred when a portion of Tatooine was engulfed in the shadow casted by one of its three moons which fully or partially blocked the light from one of its two suns, or was he speaking rhetorically as if thinking of the contrasting camera panning from the dark sea of stars to the bright picture of Tatooine, or is it the one caused by the shadow of the giant Imperial Star Destroyer in pursuit of the small Rebel Blockade Runner experienced by an observer on Tatooine?

One of the cards of the Customizable Card Game based on the Star Wars fictional universe depicts the planet Tatooine -with two moons in the background- that appear to emerge from a total solar eclipse caused by the shadow of its third moon. The aforementioned could shed some light (or shadow) on this question.

Answer 1

Apparently just a sunrise

This script element carries over from previous drafts. Going way back to the beginning, here are some excerpts from the 1974 rough draft:

1. FADE IN:

SPACE

A sea of stars is broken by the vast blue surface of the planet, Utapau. Five small moons slowly drift into view from the far side of the planet. The main titles are followed by a roll-up:

[...]

21. MED VAC EMERGENCY ROOM - UNDERGROUND FORTRESS

[...]

WHITSUN: I have tapes...A giant space fortress....

He struggles to give General Skywalker his ring.

GENERAL: As big as our Third Moon?

WHITSUN: Bigger. It's unlike anything I've ever seen. Sophisticated deflection systems.... work in opposition to the suns.

GENERAL: They will show up on our screens at sunrise. They'll attack before that.

[...]

29. SPACE - AQUILAE IN ECLIPSE

The eerie, reddish-yellow planet of Aquilae slowly drifts into view from total eclipse. A small, bright speck, orbiting the planet, sparkles in the light of the twin suns. The six deadly Aquilaean starships settle ominously into the foreground, moving swiftly toward the orbiting speck. As the sleek starships move closer, the orbiting speck is revealed to be a gargantuan space fortress.

_{(The Star Wars - 1974 rough draft; emphasis added)}

Given that it's established that the Death Star Space Fortress is going to attack just before sunrise, and that when the "eclipse" happens, there's no mention of anything blocking the suns, it seems like the intent is that the bright surface of Aquilae is coming into view from the perspective of the audience. That is, the word "eclipse" is used to describe the night side of the planet as the terminator line gradually brings it into daylight, similar to the title scene of 2001: A Space Odyssey:

30. AQUILAEAN STARSHIP - INTERIOR

Pilot Leader, in the first ship, signals to his navigator who sits in a small, isolated glass bubble to the rear of the craft. General Skywalker is seen on one of many monitors. A view of the space fortress is on another. The rest are filled with various computer readouts and displays. One of the other starships reports to Pilot Leader.

DEVIL SIX (intercom): Look at the size of that thing! Hey, Bowman, I hope you remembered to bring your pop gun, 'cause I think we caught us a big one this time....

Hmmmmm...

By the second draft, the descriptions of Utapau and Aquilae's establishing shots had been combined into one:

FADE IN:

1. SPACE

A vast sea of stars is broken as the warm, amber surface of the planet, UTAPAU, emerges from a total eclipse. Five small moons slowly drift into view from the far side of the planet. The MAIN TITLE is followed by a ROLL-UP:

_{(Adventures of The Starkiller: Episode One "The Star Wars" - 1975 second draft; emphasis added)}

In the third and fourth drafts, the first shot of Utapau/Tatooine is more or less unchanged, so it seems like these are all meant to be "planet at sunrise" imagery reused from the rough draft, even if it didn't make it into the finished film.