I concur its a sexy Ubuntu design!

I still acknowledge the iPhone 4 (S/5) with the best design out of any phone...
...in terms of corners (don't eat up much room, don't stab you)
...in terms of sides (square/flat makes it easy to hold and maximises grip)
...in terms of branding (everything is at the back, front is clean)

and that's it. But its patented

A way forward on that design would be to...
1- Front Stereo speakers (I've said this for years, HTC One listens)
2- Almost no bezel on the front (Keep saying this, little do they listen)
3- Glass only front (like the Gnex and the N9)
4- Symmetric style (place 4 hardware buttons on right side, when phone is flipped over nothing's changed)
5- OtherHalf (Jolla's got a great idea, but poor execution. Have a thin phone with small battery that can transform to anything***)
6- Have a KickStand + several forms (little 4ins, to medium 4.6ins, to large 5.2in designs)

Eg/
Original - 7mm, only 1,400mAh battery
Medium attachment - 9mm, 2,600mAh battery
Fat attachment - 13mm, 3,900mAh battery
QWERTY attachment (also comes in different layouts like azerty etc, no need to buy a different phone!)
GAMEpad attachment (something basic like three action buttons, two sets surrounding a pair of PSP-style nubs. Four shoulder pads, maybe use the 4 buttons off the phone?)
MISC attachments (second touchscreens, to LED flash, to novelty sh ites etc etc)