The Previews tab renders seven platform mockups from your page’s actual Open Graph + Twitter tags.

Platforms

Facebook - og:image 1.91:1, og:title, og:description, hostname.
Twitter - splits into summary (1:1, side-by-side) vs summary_large_image (2:1 hero) based on twitter:card value.
LinkedIn - identical layout to Facebook with platform label swapped.
Discord - embed style (colored left bar, title, description, image).
Slack - unfurl style (vertical bar, blue title, image below).
Google SERP - search snippet with favicon, breadcrumb URL, blue title, description.
iMessage / WhatsApp - chat bubble preview.

Fallback chains

Platform	Title	Description	Image
Facebook	`og:title` -> `<title>`	`og:description` -> `description`	`og:image`
Twitter	`twitter:title` -> `og:title` -> `<title>`	`twitter:description` -> `og:description` -> `description`	`twitter:image` -> `og:image`
LinkedIn	`og:title` -> `<title>`	`og:description` -> `description`	`og:image`
Discord	`og:title` -> `<title>`	`og:description` -> `description`	`og:image`
Slack	`og:title` -> `<title>`	`og:description` -> `description`	`og:image`
Google SERP	`<title>` -> `og:title`	`description` -> `og:description`	favicon (from `<link rel="icon">`)
iMessage	`og:title` -> `<title>`	`og:description` -> `description`	`og:image`

What happens when a tag is missing

Each preview card stays visible even when source tags are absent. Images degrade to a frosted gradient placeholder labeled “no og:image”. Title falls back to <title> or (no title). Description falls back to an empty string (renders as zero text).

Above the preview row, an amber callout flags whichever required tag is missing, with a copy-snippet button to fix it.