I am currently trying to set up my site using this theme and am having trouble getting the images in my portfolio to grid like on the demo site. Currently it is displaying them in a line vertically down the page instead of creating a collage. I cannot find anything in the theme settings that would fix this or in the documentation. Please help! A link the the site is http://www.refiningfirepottery.com
You need to create post for the portfolio section and assign that post to one category. After that you can follow the step:
Configure Masonry Section
Go to Dashboard >> Appearance >> Customize >> Homepage panel >> Masonry Section.
Add the Section Title on the box.
Choose the available Category from the drop down option.
Add the Button Label and URL on the box.
Then, click on Save & Publish button.