As predictable as day following night, Huawei has followed Samsung's lead and, just days after we saw the Galaxy Fold for the first time, has announced a folding smartphone of its own.

Called the Mate X, the new Huawei was revealed on stage at a press event in Barcelona, on the eve of Mobile World Congress, the world's largest phone show, which kicks off in the Spanish city tomorrow (February 25).

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Thanks to advances in flexible display technology, folding phones are expected to be a hot topic in 2019. The timing for them is crucial, given the sense of stagnation felt across much of the smartphone industry, with consumers jaded by handsets all looking the same and offering the similar sets of features.

Folding phones, which are also expected from Motorola and others through 2019, could help to inject some life into the market, albeit with even higher prices.

Although still described as a folding smartphone, the Huawei Mate X takes a different approach to the Samsung Galaxy Fold. Where the Samsung has a small display on the outside and a larger one on the inside which opens as the phone unfolds, the Huawei has a single flexible display which unfolds from the size of a phone to the size of a small tablet.

When folded open, the Huawei Mate X has an 8-inch displayHuawei

As such, when the phone is closed the display wraps around the front and back, but with the back switch off. When closed, the front of the phone has a 6.6-inch display, far larger than that of the Galaxy Fold, which has large blank spaces above and below the front 4.6-inch screen.

Perhaps the best way to look at these two phones is that the Samsung is a phone which folds open, while the Huawei is a tablet which folds closed. Whichever way you cut it, the smartphone industry has had some real energy injected into it this week, and with Mobile World Congress formally opening tomorrow, there is still plenty more to come.

When closed, the rear screen of the Huawei measures 6.38 inches and can be used as a way to take selfies with the rear camera, as the back display acts as a viewfinder.

When folded open, the Mate X has an 8-inch display with a 7:1 aspect ratio and a resolution of 2480 x 2200. There is also no notch and cut-out around the display, unlike the Galaxy Fold, which has a rectangular cutout in the top-right corner of the display when folded open.

The Mate X is a tablet which folds up, rather than a phone which folds openHuawei

The folding hinge, Huawei says, contains over 100 components and has been worked on by the company's engineers for three years. When open, the Mate X is just 5.4mm thick - slimmer than the 2018 iPad Pro - and when closed it measures 11mm

By folding in the way the Mate X does, it uses the Leica-branded rear camera for selfies, while giving the subject a view of themselves on the display.

Samsung plans to sell both 4G and 5G versions of the Galaxy Fold, while Huawei will skip the former and offer the Mate X with 5G (plus compatibility for 4G and 3G networks, as you would expect). Inside, there is a 4,500mAh battery and Huawei's own Kirin 980 processor.

Huawei is pricing the Mate X at €2,299 (around $2,600) and says it will go on sale around the middle of the year, a few months after the Galaxy Fold, which lands in the US in late-April and Europe in May. Huawei is being vague for now as the phone's availability depends on when 5G networks will be rolled out to consumers. The Mate X has 8GB of RAM and 512GB of onboard storage.

Of course, US availability is more of an unknown, given the current lack of Huawei devices available through official retail channels, and ongoing investigations into Huawei's mobile network infrastructure business.