Simple Question Re: Image in Portfolio Grid

If you look at the Home page of the basic Enfold demo, you’ll see a grid with 3 images just under the line “SHOWCASING YOUR WORK HAS NEVER BEEN MORE FUN”. The area looks like a Portfolio Grid to me, but with images about the portfolio descriptions. How was this built – what layout element is this? I would like exactly this on my home page – large images with one line descriptions underneath, that take you to portfolio pages when clicked. I downloaded the demo and filled it with my own text, but the portfolio grid will *not* show images. I have, of course, added preview images and images to the portfolio item itself, but no image shows up on my home page. I am using the Portfolio Grid – is that the incorrect layout element?
Thanks,
Jordan