Xiaomi continues to work on its foldable device but it wasn't ready to be shown at Mobile World Congress 2019.

Pocket-lint spoke to Xiaomi senior vice president, Wang Xhang, who explained to us that, while development of the foldable phone is advanced, it is very much a work in progress.

The company was expected to showcase the foldable smartphone-come-tablet during its MWC press conference in Barcelona on Sunday, but the device was notably absent.

Xhang told us that, even though the company's CEO revealed the device at the start of 2019, the project is still in its early stages: "The foldable device can offer a unique service, but it shouldn't just be about having a device that's foldable. We are still working on it." he said.

"The foldable display is only one technology and you have to integrate others. We are still studying what should be offered. There are lots of internal discussions. Everything is possible."

Xiaomi CEO Lin Bin first showed the phone in a video released at the end of January, calling it a "double folding mobile phone".

By folding both sides, it creates a smaller phone unit from a much larger 4:3 tablet. The design approach is very different to that of Samsung and Huawei. 

Smartphones with foldable displays allow a device to go from being the size of a phone to the size of a tablet.

They have burst onto the scene in 2019, starting with the release of the first commercially available foldable device in January, the Royole Flexpai. Since then, both Samsung and Huawei have announced the Samsung Galaxy Fold and Huawei Mate X respectively.

With so many engineering obstacles and high manufacturing costs - the Mate X will cost €2,299 (£1,997), for example - phone makers will want to make sure their products sell.

There are also many unanswered questions around how they work on a day-by-day basis. What will the screen durability be like? Will the software adapt well? And is there is a need for foldable phones in the first place? 

It seems Xiaomi is taking the time to ask all those questions itself.