Why is my background blurry? Mobile

[Android Central Question]

I made a 4k Picture to my background on my honor 9 and it went blurry. Can someone help?

 

[Rukbat]

The phone has a 2k screen, so you're displaying a 2k version of a 4k picture. Depending on how they're doing that (displaying every other pixel, combining even and odd pixels), that could blur the picture.

 

[gillyallan]

You've not used the illusion part of adding the picture by chance?