By default the like icon is represented on displays as a heart. If you wish to change that to any of the other available icons, follow the steps below:
Step 1. Login to Rivet Works
Step 2. Scroll down to Displays and hover over the display you wish to edit and click on Settings.
Step 3. Scroll down until you see Display Options in the left-hand side of the display configuration panel and click on "Display Options."
Step 4. Scroll down until you see the "Like icon:" setting. Make your selection from the pull-down then save your changes.
Step 5. To see the change, refresh the page where the display is present on your site.