diff -r bcda5cadab9e -r 8bd3d7b56bda src/pyams_portal/resources/css/portal.css
--- a/src/pyams_portal/resources/css/portal.css	Fri Oct 18 16:50:44 2019 +0200
+++ b/src/pyams_portal/resources/css/portal.css	Fri Oct 18 16:55:06 2019 +0200
@@ -74,6 +74,16 @@
   border: 1px solid #7b939c;
   min-height: 40px;
 }
+#portal_config .wrapper-image,
+#portal_config .wrapper-imagemap {
+  width: 100%;
+}
+#portal_config .wrapper-image img,
+#portal_config .wrapper-imagemap img,
+#portal_config .wrapper-image svg,
+#portal_config .wrapper-imagemap svg {
+  width: 100%;
+}
 #portal_config.container .col-12 {
   float: left;
   width: 100%!important;