score:7
The picture is from Tokyo taken from the SkyTree and looking toward the Mount Fuji.
Same perspective from this Tokyo Skyline & Mount Fuji 4K Wallpaper / Desktop Backgroung by Loek Janssen:
4K Wallpaper / background of the skyline of the city of Tokyo. with Mount Fuji in the background. Photo taken from the SkyTree:
(image source, CC BY-SA 3.0, taken by Kakidai)
I agree with the OP, I have no idea what the commenters above expect for "more information" since the OP simply saw the picture as a background on some computer/TV, unless there is some way to get meaningful filenames, in which case that'd probably directly solve the question and that's a question for SU. There aren't that many large cities in the world anyway. I'd expect that many "road warriors and seasoned travelers" who are supposed to be on this Stack Exchange website should be able to recognize it. Not to mention that the picture was taken from the tallest tower in the world, so it's not like it's some arcane location...