Where the feature needs work, I felt, was in its ability to control menus and scroll through text. Quick side swivels brought up hidden menus on certain screens. Like on the music screen, a quick swivel to the left brought up a panel from the right side that showed song lyrics. A quick swivel while in the second-screen TV watching app, X-Ray, toggled between character photos when they were in costume and in street clothes. In the maps app, a quick swivel brought up local Yelp listings for restaurants. When on a website, tilting the phone away from you makes the words scroll up. Tilt it more, and they move even faster.
In a way, these operational functions made me feel uneasy because I don't want to necessarily keep my head still while using my phone all the time, or set off unintended actions. And these things were definitely possible. While looking at a product image on the Amazon store app of a bottled product that was identified using Firefly, the image erratically jumped between big and small. I just wanted it to stop.
This phone has other features, and basically it's very nicely built. It has a solid heft in the hand while not being heavy at all. The buttons, which can activate the camera or Firefly from a cold start, are minimalist and comfortable. The 4.7-inch screen with a 16:9 aspect ratio is just right for holding and controlling with one hand. There are speakers on top and bottom for stereo sound when holding the phone sideways.
And it is packed with many of the features that Kindle Fire tablet users are familiar with, such as its Mayday live-help function. It is a tool for reaping all of the benefits of a $99-a-year Amazon Prime membership, from video watching to music listening to book reading. And you get one year of Prime for free.
Yet it's the dynamic perspective feature that, in my view, changes smartphones forever. It's one that others may try to copy, and I think it opens up a world of possibilities for app developers.
Before the event, Amazon CEO Jeff Bezos sent all attendees a copy of his favorite children's book, "Mr. Pine's Purple House." The moral of the story is that it's good to be different sometimes.
In an interview with The Associated Press after the event, Bezos responded to several questions surrounding Amazon's late entry into smartphones and the dominance of existing players like Apple and Samsung. Bezos rebutted: "Taken to its logical extension, you could never have new entrants in anything," and laughed with his signature guffaw.
This is a purple house and inside there are 3-D images in floating picture frames of tofu sculptures suspended by hot-air balloons. Many people will want to live there and it's absolutely worth taking a tour.
Follow Ryan Nakashima on Twitter at https://twitter.com/rnakashi