Index: wordpress.org/public_html/wp-content/themes/pub/wporg-photos/css/components/_site.scss
===================================================================
--- wordpress.org/public_html/wp-content/themes/pub/wporg-photos/css/components/_site.scss	(revision 11726)
+++ wordpress.org/public_html/wp-content/themes/pub/wporg-photos/css/components/_site.scss	(working copy)
@@ -167,6 +167,10 @@
 body.single-photo .site-main {
 	float: none;
 	max-width: $size__site-main;
+	@include breakpoint( 0, 960px ) {
+		margin-left: 20px;
+		margin-right: 20px;
+	}
 }
 
 body.single-photo {