Would be awesome if we could customize the content for form unfurls (a la url previews in slack). Right now they all unfurl as shown in the screenshot
If you go to the settings tab → seo, you should be able to set a title tag, meta description, and open graph image for each of your forms
And you can also set a custom favicon in your account settings under branding - this would apply to all forms in your account (seo settings are per form)