anyone knows if this is a gallery plugin or a modified theme?

Hello! I’ve been wanting to have this plugins/hack for 3 years, I found some threads on it but weren’t resolved: http://wordpress.org/support/topic/how-to-create-a-page-like-this?replies=5 I was wondering if someone could point me in the right direction:

I’d like to have a gallery in the post ie: http://www.thesuperficial.com/lindsay-lohan-bikini-hawaii-12-2011

that when clicked will show the image page with a blog excerpt and “back to article” link ie: http://www.thesuperficial.com/photos/lindsay-lohan-bikini-post-playboy-photos

I believe I have to modify the theme and what it “calls”but Im not where to start. The sites I’ve seen this are almost all sites from celebuzz: thesuperficial.com justjared.com http://www.wwtdd.com kimkardashian.celebuzz.com

They also have very nice organized photo/video gallery by tags/category
so im not sure if its a plugin or the code has been modified and its driving me crazy all this searching, testing and failing :S

Any help will be very much appreciated!
At the moment im using 2.9.2 but im planning to update once I find out to do this gallery.http://www.sofiaworld.com