Why 7?

Google just announced its home-made delicious Jelly Bean tablet- Nexus 7, the first of, I believe and hope, many more Nexus series of tablets to come. Check out the Verge review right here. I just want to point out one thing, and ask one question.

What I want to point out is that how much I appreciate Google NOT putting a camera at the back.

What I want to ask is WHY 7?

As far as I know, there have been 4 Google flagship phones, the G1, Nexus One, Nexus S and Galaxy Nexus. Even if I count the Honeycomb tablet, there has only been 5 flagship devices so far. What's the 7 about? Did I miss anything?

Maybe it's the screen size, 7 inches?

Leave comments below and give me your thoughts on this.