Basically what it shows is the Mormon 'endowment', which is supposed to prepare the cultists for becoming the kings and queens and priests of the afterlife/heaven... it seems like it's the Mormon version of, essentially, a confirmation ceremony. Sort of. Wikipedia explains it here:
Endowment (Mormonism). It doesn't make it any clearer.
I've seen parts of it before but didn't watch this whole one. From what I've seen previously, it's a long, culty church service but most of the audio has been hard to decipher and not all of it is subtitled. It tells them how to conduct themselves when they get to the gates of heaven, how to answer questions, a 'password' or some shit to get into heaven, which if you don't know apparently they pull the Trapdoor to Hell on you, and they give you your 'special spiritual name' or something. This guy gets called 'Eli'. I've also found out that everybody gets the same name at these events, so all the guys there were called 'Eli', and all the women would've gotten another name. Since you're forbidden from telling anyone what your Secret Magical Mormon Name (TM) is, nobody is likely ever go catch onto this.
It's all just as weird and flagrantly cultlike as it sounds.
As far as I know, this is pretty real as well.