Correct me if I'm wrong but wasn't this section of the game the demo that was available at the Comic-cons before the delay? In fact it was used as the preview when Ryan French debuted it on X-Play.
http://www.youtube.com/watch?v=poWJq6kEPNE

So yeah I think it makes sense that it's used to try and convince potential buyers that it's worth picking up. You got a little bit of everything in it.
I'm also going to link this video, which I'm sure most us haven't seen in close to year, because it's interesting to notice all the differences between the final version and what was initially introduced to the public.

http://www.youtube.com/watch?v=xnLbwJgeUSY

superstarseven;151516
So yeah I think it makes sense that it's used to try and convince potential buyers that it's worth picking up. You got a little bit of everything in it.
I'm also going to link this video, which I'm sure most us haven't seen in close to year, because it's interesting to notice all the differences between the final version and what was initially introduced to the public.

I noticed they don't introduce the stasis beam and shock blast at the start of the library as they do in the final version. Probably as to not give to much away in a demo version.

heslimedme25;151519
I noticed they don't introduce the stasis beam and shock blast at the start of the library as they do in the final version. Probably as to not give to much away in a demo version.

and also the ghost vapor trail isn't there either. Everything goes by the PKE in the final. Also, the possesed library cart should meet you before entering the big room where you fight the Book Golem isn't there.

well I'll be,

guess all the demo whiners finally got their demo

Buckynohair;151514
I downloaded the demo on PSN and it was the library.

I haven't DL'd it, but the title said it was the Ballroom.(*winston)

That's strange. Maybe Pal and NTSC have gotten different versions of the demo on Ps3.