For some reason, Macrumors is not letting me attach a link to a picture, but:
Here is a link to a page that shows a slight backlight bleed in the corners. Mind you, this picture was still not taken with the proper exposure so what you're seeing here is exaggerated, but it shows you what I mean:
https://forums.imore.com/macbook-pro/394731-backlight-bleed-2017-macbook-pro-touch-bar.html
Also, please don't confuse this with IPS glow...although it can look similar to it.
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I would suggest going in a pitch dark room, set the brightness to max and run Test Screen then Pixel Checker, scroll through the colours until the pure black screen from this website...you will need Adobe Flash installed:
http://imac.squeaked.com/test.php
Again, your screen will be brighter than your room since it's not a OLED (where each pixel is not lit on pure black), but you're looking for consistency in the screen without any sort of bright patches, clouding or flashlighting. Let us know what you see.
You don't have to wait until it gets dark...just go in a room with no windows, shut the door and turn the lights off.