--- a/src/web/app/themes/twentynineteen-child/style.css	Tue Jun 18 11:46:50 2019 +0200
+++ b/src/web/app/themes/twentynineteen-child/style.css	Thu Jun 20 18:15:23 2019 +0200
@@ -134,6 +134,8 @@
 
 .entry .post-thumbnail .post-thumbnail-inner img {
     position: relative;
+    width: 100%;
+    height: 100%;
 }
 
 .image-filters-enabled .entry .post-thumbnail:before {