There are 2 kinds of Boxes on One Profile
Essential Boxes are boxes that are fixed on certain columns and arrangements. They can't be rearranged and their titles are not editable. They can, however, be removed from your page to make way for Custom Boxes. Essential Boxes are a quick way to set up your profile page and is meant primarily for non-unicorn owners.
Custom Boxes are customizable floating blocks on your profile page consisting of a title and a content. With Custom Boxes, you can personalized your page by adding customized call-to-action buttons to bring visitors to your Patreon page, your Substack newsletter, your Medium page or literally anywhere you want on the internet. You can even write long texts, post linkable pictures, embed YouTube videos, Instagram Galleries, and Twitter Timelines, display Google Maps, and also testimonial boxes.