In a nutshell: It's been discovered that setting a certain image as a wallpaper on some Android phones can soft-brick the devices, causing them to crash and get stuck in a loop that turns the display on and off, making it impossible to get past the lock screen.
Prolific leaker Ice Universe highlighted the issue on their Twitter account. It seems to affect most Android devices, especially Samsung's. Android Authority writes that setting the image as the wallpaper didn't affect a Huawei Mate 20 Pro, but it did crash a Pixel 2. It also crashed a Pixel 3 XL, according to 9To5Google, which discovered the cause of the issue.
WARNING!!!
--- Ice universe (@UniverseIce) May 31, 2020
Never set this picture as wallpaper, especially for Samsung mobile phone users!
It will cause your phone to crash!
Don't try it!
If someone sends you this picture, please ignore it. pic.twitter.com/rVbozJdhkL
It turns out that the phones don't support the color space of the image. Instead of using Android's preferred sRGB, it uses the RGB color space, which Android 10 doesn't convert. That means any incompatible handsets will be soft-bricked.
Thankfully, the devices can be recovered. You can restart in safe mode and delete the image file, or you can use the bootloader to reset the phone completely.
It's noted that with the Android 11 preview, the system converts non-supported color spaces, which allowed the image to work on a Pixel 4 XL running Android 11.
It turns out that a similar problem was reported in Google's Android issue tracker back in 2018, but Google developers said they were unable to reproduce the effect and closed it out.
According to Ice Universe, Samsung received feedback on the bug in mid-May and has resolved the issue. "Just wait for the subsequent firmware update and do not take the risk," they tweeted.
Update: Samsung has received feedback on this type of bug in mid-May, and has resolved this issue. Just wait for the subsequent firmware update and do not take the risk. pic.twitter.com/oa7rxnkSkb
--- Ice universe (@UniverseIce) June 1, 2020