This texture is supposed to represent a metal surface, so let's make the material shiny. There are a couple ways to do it, but let's use this opportunity to learn about a new node type—a Constant.
Find the word Constant in the Material Expressions list, and drag it into the editor viewport.
Connect the new Constant node to the Specular rendering terminology for shininess input on the left.
It didn't seem to have any effect. Right now, the constant has a value of
0
, which means no specularity. Select the constant, and then at the bottom of the window, in the properties window, you'll see it has an R value of 0.000000. Change it to2.000000
:Rotate the Preview cube around and you'll see that now it's much shinier.