I guess this is for a person that want's to get an offline copy of the 4GB DMG to make a USB drive with Lion Installer without having to buy an additional copy Lion from the Mac App store @ $29.99 & do it the legal way. :)
When a person buys a mac that shipped with Lion, he does not have access to the DMG file on the drive, so if his drive needs to be re-formatted and wants to avoid the trouble of downloading a copy of Lion every time by using the Command-Option-R (force internet lion recovery), then this is a legal way to get an offline copy of InstallESD.dmg which can be used for any future installation of Lion.
UniBeast seems to do a lot of stuff and very interesting.