I don't believe your comment was intended to be constructive at all. It sounds much more like jealousy and looking for an excuse to tear down someone who's put in great effort.
The concept and presentation of it are definitely impressive, especially for someone who's only 21 and still looking for internship-level work. He's easily in the top 5%, probably top 1% of designers, in terms of being able to see a complicated concept through from ideation to execution.
#1 — There's nothing wrong with using assets from other companies like Amazon, Facebook, Wikipedia, etc. in a concept mockup. If anything, it's nice to see realistic assets being used instead of stock junk that won't actually work in real-world situations.
#2 — Yup, the 6-finger-pinch would probably be too convoluted, I agree. But that's easily replaced with a regular pinch. Easy to get little details like this wrong in the scheme of things, especially for the more minor gestures.
#3 — Who cares? If anything this shows that he knows about what's out there in terms of prior art, and is able to build on it in an inspiring way. That's a good sign in my book, not a deal breaker.
#4 — The fact that he was able to put together this page, with all of the marketing copy, and the well-design screenshots (with zooming), etc. already shows that for a visual and interaction designer he's way ahead of the curve in terms of marketing.
I'm not saying the concept is perfect, but it's definitely well presented, and well thought out. Add in the fact that the designer is 21 and looking for an internship, and he is an absolutely obvious candidate for a phone screen. I'd be surprised if he isn't able to land internships with any of the big tech companies (Apple, Google, Facebook, etc.) with this piece as part of a larger portfolio. He's clearly good at coming up with, polishing, and communicating ideas.