Shadow on the screen

In my Note 5, when the backlight is on, a shadow is visible at the bottom in the place marked below. It is most visible in a dark room. I got a second Note 5 today. The second has this shadow at the bottom less visible but in the center of the screen there is a bright spot when the backlight is on. I do not know what to think about it. This shadow at the bottom has a greenish-blue tint when the cool light is on. This is normal ?