Tack said:

Sure. It's a digital upgrade to the original Rinzler 'Making of' books, with new pieces of behind the scenes footage unearthed from Lucasfilm's vaults.

I remember a few of them:

Luke, Han, and Leia waltzing through the hallways with the weapons behind their backs.

The original crawl.

Editorial version of the opening strike (more Antilles dialogue)

Various other odds and ends (some of the original lightsaber footage, if I'm not mistaken)

Does the eBook you're talking about include these bloopers by chance: http://www.youtube.com/watch?v=OgLl0_mqLtc? And is based off this book: http://www.amazon.com/The-Making-Star-Wars-Definitive/dp/B00DT6BGFA/ref=sr_1_11?ie=UTF8&qid=1396406113&sr=8-11&keywords=The+Making+of+Star+Wars+rinzler ?