How I can attach an image to a a grid cell?

I am new to lightning and just want to know how I can attach an image to a grid cell.

A Grid is just a container to add additional Lightning Components to. You can add an image by adding another object like:
{MyImage:{ x: 250, y: 100, src: '/Lightning/img/LngDocs_LilLightningIdle.png' }}

Use Grid.add