Would the burn-in get worse than what is being shown in that pic going around the internet? Will it get darker than that as more time goes by?
I really have zero experience with screen burn-ins (it's so strange I'm seeing this on a phone in 2017!) so I ask. Thanks.
If it is indeed burn-in then yes it will get worse as time goes on. If it's image retention then it shouldn't since it should reset and fix itself after you leave the phone off for a bit or play something with motion.