What just happened? Remember the Essential Phone, a 2017 handset from the company created by Android co-founder Andy Rubin? A successor has just been revealed, and it's very different from your usual flagship.

Former Google executive Rubin, now CEO of Essential Products, tweeted out images showing a prototype phone called Project Gem. The most noticeable detail is the long and thin design---it's about half the width of a standard smartphone.

Rubin also highlighted the new UI for Gem's "radically different" form factor. It appears to consist of several card-style apps packed onto the display and some pretty hefty on-screen buttons. We also see a volume rocker and power button on the right side, while the rear shows what looks like a fingerprint sensor and a large, single camera.

While it might have been Apple's iPhone X that started the trend for smartphones with notches, it was the original Essential phone that first sported a cutout in the display. With the successor, it seems Essential has turned to the newer pinhole-style of cutout.

Another feature of the phone is the four reflective "colorshift material" rears, which change color depending on the angle you're viewing them. Additionally, the phone is rumored to be controlled mainly through voice commands, with an AI assistant performing many of the tasks.

"We've been working on a new device that's now in early testing with our team outside the lab. We look forward to sharing more in the near future," Essential said, in a statement.

Rubin left Google in 2014 following accusations of sexual harassment and coercion, which he denies. After founding Essential, the company launched the PH-1, which received some mixed reviews. It didn't sell very well and the promised modules never really arrived. The phone was discontinued in December.