1. The centers of rotation aren't fixed, i.e. when you see the side profile, they're much closer together. I think this makes it easier to compare them side-by-side, especially when trying to compare thinness.
2. Rotation is restricted to only two axes (vs. all three). It's surprisingly difficult to control a 3-axis gimbal with only 2 axes on a screen. For those who aren't familiar with 3D CAD/modeling, try orienting this gimbal simulation  in an arbitrary angle (or doing a barrel roll). Restricting it to two axes also keeps the models from going into orientations that probably aren't very useful for the user.
I don't know the first thing about "3D UX," but I thought they were good, albeit subtle, interface decisions.
Whilst there are websites that let you compare the specs of phones, we wanted to compare the shape and size. There are currently 19 phones on Hotspot 3D, but we actually have the models for many more. We just chose the most popular ones for now.
It's especially difficult to tell the difference between 'plus' models without a physical reference, so that is where this idea came from.
The phones themselves are around 1.5MB each and are rendered using our own custom engine in webGL. The java-script itself is only 40kb, and works on mobile as well.
Thanks for taking a look, and I would love to hear any feedback or comments you have.
Is it possible that the Hotspot version will ever contain a comprehensive catalog, or would that dig into sales of the main product? Could you add a back-catalog to Hotspot without impacting sales?
Can you handle phones with moving parts? e.g. QWERTY sliders like the Xperia Mini Pro, or addons like "Moto Mods" or the Essential PH-1 360 Camera.
Are you in discussion with any of these "websites that let you compare the specs of phones"? That sounds like a great match.
1.5MB sounds a bit large when most phones have quite simple geometry. Where does the file size come from?
Moving parts is something we have experience with but have not included in the current version.
1.5MB might indeed sound a lot if you compare it to a single image. On the other hand if you look at a regular 360 viewer this takes often about 10MB of data. Also we want the phones to look really (really) good. This means that we need to put quite a lot of detail into things like corners and buttons.
On-topic. Still awesome to flip around. I like how the compare mode is made to smartly position the two phones based on viewing angle so they align best for the comparison you likely want to make for that angle.
The core team is about 10 people, and we do projects like this every now and then. :)
Congratulations, one of the few times I see a worthwhile use of WebGL beyond games.
Just needs more models in there...