Meanwhile, for everyone not seeing what the fuss is about, here's the correct link:
Are your government's internet filters too aggressive?
Or do you just have nothing else in life to complain about?
Especially "ze first" image as seen in FF and Chrome.
I suppose it is related to how monitors use temporal dithering to fake 24 bit colors when they really have 18 bits per pixel, but why is it more apparent on this kind of picture?
Is it a perceptual issue or a technical one?
It is also apparent when using Windows XP under virtualization. Some windows have checkerboard patterns that flicker.
tl;dr: the liquid crystals in LCDs need to be driven with AC voltage to prevent electrolysis degradation. This is known as "inversion" and there are different patterns used. If the magnitude of the + voltage is different from the - voltage, i.e. the "common" voltage Vcom is not exactly in the middle, the subpixels change brightness slightly on each cycle and this causes flicker. The flickering becomes much more noticeable if the pattern displayed in the image matches the inversion pattern.
Neither of my (nearly 10 years old now... but still working well) LCD monitors flicker on all the images, so this is something that shouldn't be occurring on a good monitor. I suppose manufacturers now are relaxing the tolerances to save cost, justifying it by the fact that flickering is not observable on "most" (debatable) content.
As another commenter mentioned these effects are called Moiré patterns: https://en.wikipedia.org/wiki/Moir%C3%A9_pattern
They may be more or less apparent depending on the scaling on the image and the scaling algorithm being applied. Some scaling algorithms apply filters that can make the effect even more weird than normal.
Here is great article about it. It is a few years old, so some of the problems are fixed now. https://hsivonen.fi/png-gamma/
Sorry my Google-fu failed and I can't find the link.
Here's a good illustration that shows how the pixel values of the 2 images have been "compressed" into two separate ranges: