The Promo Boxes are the 2, 3 or 4 linked image boxes that you can choose to display on your home page. These boxes are set up via the Customizer settings.
For setup directions for the Blog Page Promo Boxes, see this article.
How to setup the promo boxes
1.In the Dashboard, go to Appearance > Customize to open the Customizer.
2. Find the Home Page Settings panel. Click to open the panel.
3. Find the Home Page Promo Boxes section. Click to open the options section.
4. Under the Home Promo Layout option you can choose to display 0, 2, 3, or 4 promo boxes on the home page.
5. Under Promo Boxes Height select the height of your promo boxes in pixels. Use the up/down arrows or enter your number directly.
6. Each Promo Box has 3 settings: Title, Image & URL.
The Promo Boxes are numbered 1 through 4 from left to right. If you enable 3 Promo Boxes, fill out the fields for Boxes 1, 2, & 3. If you fill out the details for Box 4, it will not appear on your home page unless you set the layout to display 4 Promo Boxes.
5. The Promo Box Title is the title on the overlay. This field is optional.
6. Select a Promo Box Image by clicking on the Select image button. If you need to change images, click the Change image button. You will be able to add an image from your computer or Media Library.
7. For the Promo Box URL, this is the web page address that you want the Promo Box to link to.
You will need to copy and paste the link into this box. The easiest way to do this is to visit the page or post and copy and paste it from the top bar of your web browser.
8. Fill out all fields for each Promo Box.
9. Click the Save & Publish button to publish your Promo Boxes.