Index: admin/metabox/class-review-tools.php
===================================================================
--- admin/metabox/class-review-tools.php	(revision 5564)
+++ admin/metabox/class-review-tools.php	(working copy)
@@ -12,7 +12,7 @@
 
 		$zip_files = array();
 		foreach ( get_attached_media( 'application/zip', $post ) as $zip_file ) {
-			$zip_files[ $zip_file->post_date ] = wp_get_attachment_url( $zip_file->ID );
+			$zip_files[ $zip_file->post_date ] = array(	wp_get_attachment_url( $zip_file->ID ), $zip_file );
 		}
 		uksort( $zip_files, function( $a, $b ) {
 			return strtotime( $a ) < strtotime( $b );
@@ -20,12 +20,14 @@
 
 		if ( $zip_url = get_post_meta( $post->ID, '_submitted_zip', true ) ) {
 			// Back-compat only.
-			$zip_files[ 'User provided URL' ] = $zip_url;
+			$zip_files[ 'User provided URL' ] = array( $zip_url, null );
 		}
 
-		foreach ( $zip_files as $zip_date => $zip_url ) {
+		foreach ( $zip_files as $zip_date => $zip ) {
+			list( $zip_url, $zip_file ) = $zip;
+			$zip_size = ( is_object( $zip_file ) ? size_format( filesize( get_attached_file( $zip_file->ID ) ) ) : __( 'unknown size', 'wporg-plugins' ) );
 			printf( '<p>' . __( '<strong>Zip file:</strong> %s', 'wporg-plugins' ) . '</p>',
-				sprintf( '%s <a href="%s">%s</a>', esc_html( $zip_date ), esc_url( $zip_url ), esc_html( $zip_url ) )
+				sprintf( '%s <a href="%s">%s</a> (%s)', esc_html( $zip_date ), esc_url( $zip_url ), esc_html( $zip_url ), esc_html( $zip_size ) )
 			);
 		}