app/views/shared/_og.html.haml

   1 - thumbnail = @instance_presenter.thumbnail
   2 = opengraph 'og:site_name', t('about.hosted_on', domain: site_hostname)
   3 = opengraph 'og:url', about_url
   4 = opengraph 'og:type', 'website'
   5 = opengraph 'og:title', @instance_presenter.site_title
   6 = opengraph 'og:description', strip_tags(@instance_presenter.site_description.presence || t('about.about_mastodon_html'))
   7 = opengraph 'og:image', full_asset_url(thumbnail&.file&.url || asset_pack_path('preview.jpg', protocol: :request))
   8 = opengraph 'og:image:width', thumbnail ? thumbnail.meta['width'] : '1200'
   9 = opengraph 'og:image:height', thumbnail ? thumbnail.meta['height'] : '630'
  10 = opengraph 'twitter:card', 'summary_large_image'