To give you back ground info as I had this as well its about LG vs. Samsung. Both provide model and the parts that sucks is Apple bought more LG's but they are getting a whopping return of them. What they do is order the screen and replace it but you can confirm you have a Samsung model which is brighter and does not retain the image. I will also provide a link to you to test the burn in.
ioreg -lw0 | grep \"EDID\" | sed "/[^<]*</s///" | xxd -p -r | strings -6
-- This will display a few lines, if the model/serial starts with LP then you got another LG. If it is LSN (*i think) then you got a Samsung.
You can test the burn in below, I did this for the tech and he same that in 10:00 i remove the checkboard and it the image stuck. Asked nicely for the Samsung and HE was happy to do it. Some customer can be jerks I am always nice.
If its LP (LG) return while Samsung screens are still instock, people fear of them running out.
I am not a huge Apple fan as I run Windows 8 on it with Steam and work. The thin metal body + retina screen + i7 + kepler + glass mouse pad+ a store where I can ask for service like this I am very happy. It cost me ZERO and 15 min of my time. With out the Kepler I would have went with Origin Laptop in Florida.
The quality is insane and I have had Asus, Dell, HP and if ever a issue I spend HOURS on the phone and got no where. It is a terrible experience dealing with laptops the companies want nothing to do with them once opened.
With out Nvidia I would have skipped but this is the perfect storm laptop for OSX, Windows or workaholics or gamers. I use Android and Windows, Im just saying so you know I am not an apple nut but just had a good experience.
*Beware you may have to do work for a Samsung screen but its a nice laptop, after it broke my pockets I like that Apple gives me 1 year to buy a warranty so i didnt have to pay on day one. that is damn cool, 1 YEAR!