I tried to photograph the effect. Had to turn the brightness all the way down (the main screen shown is showing the same channel as the screen to the left of it).
The screen left was at comfortable viewing level, the main screen was nearly black. That's what the cheap digital camera needs I guess.
The checkerboard pattern in the light areas -- especially under the 'o' in 'Fort Wayne' -- is representative, I'm pretty sure:
unless it's just a jpeg artifact from the digital camera, that happens to look exactly like it. It was practically impossible to photograph. In real life, it's entirely noticeable and annoying. Drifts upwards as described. I'll want to defeat it with wa2ise's mod whenever I get around to my Frankenstein Project (after my current job assignment -- and associated stress level -- ends).