Start by creating a text which can be used for example as a header. Drag a text block into the structure and type desired content into the header. Once the text is finished, click on the structure which contains the text block. In the structure section, click on upload new image under background image.
Choose an image that you would like to have under the text. Important note - the block will be as big as the text block so if you want to have a bigger image displayed you can add spacers one above the text block and one under the text block.
How simple is that!