Adapt these three columns to fit you design need. To duplicate, delete or move columns, select the column and use the top icons to perform your action.
Delete the above image or replace it with a picture that illustrates your message. Click on the picture to change it's rounded corner style.
To add a fourth column, reduce the size of these three columns using the right icon of each block. Then, duplicate one of the column to create a new one as a copy.