I seriously don't even understand the pixel showing everything in the universe question.
To make it simpler, imagine a 2x1 black and white screen.
Two pixels wide, one pixel tall.
Your options for each pixel is either black, or white.
So possible configurations are
BB
WB
BW
WW
If you showed all 4 of those configurations, you would show every image that's possible of being shown on that screen.
The concept is the same, except on a MUCH much larger scale. It's making the screen show every possible combination of pixels, which would result in every possible image capable of being seen on that screen appearing.
Now, lets assume instead of a black and white screen, we have a full color screen.
That means there are 255 shades of red, 255 shades of green, and 255 shades of blue for every pixel.
So that means every pixel has 255*255*255 possible colors it can show, or 16581375 colors total.
That's for every single pixel.
A 1080p display for example, has 2073600 pixels. So (and my math may be a bit wonky here) to get every possible combination, the screen would need to show (16581375)^2073600 number of images, which is 10^(10^7.175239356116171)
To give a more easily digestible number, that's 14970606 decimal places.
So the "show everything in the universe" thing might sound crazy until you realize the fucking GARGANTUAN amount of images it would have to show to show every possible pixel combination.