Index: src/wp-content/themes/twentyseventeen/front-page.php
===================================================================
--- src/wp-content/themes/twentyseventeen/front-page.php	(revision 38875)
+++ src/wp-content/themes/twentyseventeen/front-page.php	(working copy)
@@ -48,8 +48,10 @@
 
 					wp_reset_postdata();
 				else :
-					// The output placeholder anchor.
-					echo '<article class="panel-placeholder panel twentyseventeen-panel twentyseventeen-panel' . esc_attr( $twentyseventeencounter ) . '" id="panel' . esc_attr( $twentyseventeencounter ) . '"><span class="twentyseventeen-panel-title">' . sprintf( __( 'Panel %1$s Placeholder', 'twentyseventeen' ), esc_attr( $twentyseventeencounter ) ) . '</span></article>';
+					if ( is_customize_preview() ) :
+						// The output placeholder anchor.
+						echo '<article class="panel-placeholder panel twentyseventeen-panel twentyseventeen-panel' . esc_attr( $twentyseventeencounter ) . '" id="panel' . esc_attr( $twentyseventeencounter ) . '"><span class="twentyseventeen-panel-title">' . sprintf( __( 'Panel %1$s Placeholder', 'twentyseventeen' ), esc_attr( $twentyseventeencounter ) ) . '</span></article>';
+					endif;
 				endif;
 
 				$twentyseventeencounter++;
Index: src/wp-content/themes/twentyseventeen/style.css
===================================================================
--- src/wp-content/themes/twentyseventeen/style.css	(revision 38875)
+++ src/wp-content/themes/twentyseventeen/style.css	(working copy)
@@ -2987,10 +2987,6 @@
 	}
 }
 
-article.panel-placeholder {
-	display: none;
-}
-
 .twentyseventeen-front-page.twentyseventeen-customizer #primary article.panel-placeholder {
 	border: 0;
 }