(Pocket-lint) - Sony Mobile is thought to have big plans for next spring's Mobile World Congress; it is expected to unveil the Sony Xperia XZ4 and XZ4 Compact.

Recent leaks have shown the former to have a 2:1 display. These come from alleged CAD specifications sent to case manufacturers.

However, images of what is claimed to be a screen protector have also appeared online suggesting Sony might be heading down an alternative route - breaking new ground in the process.

Serial Twitter leaker Ice Universe (@UniverseIce) claims that the proposed protector actually reveals the next flagship with have a 21:9 display - taller and thinner than most existing handsets.

As Ice Universe notes, not only will a 21:9 display present more content in portrait mode, it is better suited for movie viewing. Many cinematic releases are presented in 21:9 naturally so would fit the screen perfectly.

That being said, anyone who ever saw Philips' 21:9 Ambilight TV in action will know that the unfortunate side effect is that any 16:9 videos - such as most TV shows - will have large black bars down the sides rather than thinner ones across the top and bottom.

Still, you can't have everything.

We hope to find out more closer to MWC 2019 in Barcelona. It starts on 25 February next year.

Writing by Rik Henderson.