How do you use starter content material: M_ColorGrid_LowSpec?

I’m learning Unreal. I’m working with a standard 3d sample. I’ve created a mesh actor, and I’m trying to apply a material. I’m looking at the StarterContent, and I’m quite confused by one material listed there, M_ColorGrid_LowSpec. (Content → StarterContent → Materials → M_ColorGrid_LowSpec)

See the attached images:

Scan of StarterContent materials:


M_ColorGrid_LowSpec blueprint:


T_ColorGrid texture:


Can somebody explain what’s going on here? At first glance I would have thought that texture image is used to generate a color say with a mouse click to select a color off the block image inside the TextureSample Node. Obviously it doesn’t work that way. I see no instructions on how to use this. Can someone explain what’s going on?
Is this a learning tool, a placeholder for some other content? What RGB output is being generated here?

Color me confused.