Sony Mobile could be moving in a new direction with the Xperia XZ4 - it could be moving into 21:9 territory. We've now seen a number of leaks suggesting that the next Sony flagship device could shift to a new, taller, aspect ratio.

Over the past year we've seen a big shift from 16:9 as standard to 18:9 and beyond. As companies move to reduce bezels on smartphone displays, as well as making larger display spaces manageable one-handed, we're seeing increasingly tall screens. 

The move to 21:9 might fit neatly into that widescreen movie aspect - popularised by Philips Cinema TVs around the turn of the decade - but we've previously heard that the phone will be 158mm tall and 73mm wide. That's the same height as the Pixel 3 XL, but it's not as wide, so it's not a phone that's too big - although it will be a bit of a stretch to get to the top of the screen if using it with one hand.

Frequent leaker on Twitter @UniverseIce has shared some details, following receipt of a screen protector in that aspect.

Of course, it might be that the screen protector company simply took the measurements of previous leaks and made it into a product, but it does give a good sense of what this phone might look like if that pans out to be true. Given the measurements, we can't see that a 21:9 phone would be a problem.

The Twitter leaker goes on to ponder what the experience would be like watching a 21:9 movie - meaning a completely black bar free experience. We're sure that would be great, but with a wide range of different formats to movies, there's no single aspect that covers all possibilities.

The Sony Xperia XZ4 is expected to launch at Mobile World Congress 2019 alongside the Xperia XZ4 Compact - so if you're looking for a smaller handset, it looks like there will also be something for you.