Index: src/wp-admin/includes/class-wp-press-this.php
===================================================================
--- src/wp-admin/includes/class-wp-press-this.php	(revision 31768)
+++ src/wp-admin/includes/class-wp-press-this.php	(working copy)
@@ -926,6 +926,12 @@
 			$link = $data['_links']['shortlink'];
 		}
 
+		// If canonical link is from root (starts with /, but not //), as Vimeo.com does, be sure to fully qualify it.
+		// USe $data['u'] to define site root, because we know we force users to have them start with http[s].
+		if ( preg_match( '/^[\/]{1}[^\/]+/', $link ) ) {
+			$link = preg_replace( '/^(https?:\/\/[^\/]+)(\/.*)?$/', '\1', $data['u'] ) . $link;
+		}
+
 		return $link;
 	}
 
@@ -1001,6 +1007,18 @@
 				' <em><a href="%1$s">%2$s</a></em></p>',
 		);
 
+		$url = $this->get_canonical_link( $data );
+
+		// Try to auto-embed if on service-specific page
+		foreach ( $this->embeds as $embed ) {
+			// $embed is protocol relative (starts with //), so URl should end with.
+			if ( preg_match( '/' . preg_quote( $embed, '/' ) . '$/', $url ) ) {
+				// Use <p> for description, rather than <blockquote>, still matches expected sprintf format
+				$default_html['quote'] = '[embed]' . $url . '[/embed]<p>%1$s</p>';
+				break; // So it only happens once.
+			}
+		}
+
 		/**
 		 * Filter the default HTML for the Press This editor.
 		 *
@@ -1019,7 +1037,6 @@
 		// Add source attribution if there is one available.
 		if ( ! empty( $default_html['link'] ) ) {
 			$title = $this->get_suggested_title( $data );
-			$url = $this->get_canonical_link( $data );
 
 			if ( ! $title ) {
 				$title = $this->get_source_site_name( $data );