With the new Homestead Websitebuilder, all the designs are responsive. This means that they are automatically mobile friendly and you will not be required to do anything more to achieve this, however, you may find that you want to make some changes only on the mobile site. You can access the mobile editor at the top left of the editor, then click on the element you wish to edit. In this case I chose a text box. You will see that while you do not have the ability to edit the actual content, you may change the style and position of the box. This will only affect the mobile version. To get back to the mail site editor, push the desktop monitor button to the left of the mobile editor.