How to use the Dither option in Texture Painting

The reason I’m doing that is because at this page of Blenders online documentation:

https://docs.blender.org/manual/en/3.5/sculpt_paint/texture_paint/tool_settings/options.html?highlight=dithering

it said:

Dither

Amount of dithering when painting on 8-bit images.

How do you see this dithering in my file? Do you know?

This is my test image. And below is the render test EEVEE:

I just cannot see the effects of dithering, like this: