Shade square on upper half on Samsung Galaxy S4 ?

[AC Question]

I noticed that on the 2/3 upper half of the screen is 'square' that is slightly darker than the rest of screen.I made screenshot of the screen,checked it on my computer and there was not 'square'.Please help.

 

[belodion]

If the darker area does not show on the screenshot when viewed on your computer, it suggests a fault with the phone's display.