adjust file type icon placement for when no preview can be generated

apps/files_sharing/css/mobile.css

@@ -20,6 +20,10 @@ table td.filename .nametext {
 	padding: 0;
 	margin-bottom: 35px;
 }
+/* some margin for the file type icon */
+#imgframe .publicpreview {
+	margin-top: 32px;
+}
 
 /* always show actions on mobile */
 #fileList a.action {

apps/files_sharing/css/public.css

@@ -71,6 +71,11 @@ p.info a {
 	max-width:100%;
 }
 
+/* some margin for the file type icon */
+#imgframe .publicpreview {
+	margin-top: 10%;
+}
+
 thead {
 	padding-left: 0 !important; /* fixes multiselect bar offset on shared page */
 }

apps/files_sharing/templates/public.php

@@ -34,7 +34,7 @@
 				</div>
 			<?php else: ?>
 				<div id="imgframe">
-					<img src="<?php p(OCP\Util::linkToRoute( 'core_ajax_public_preview', array('x' => 500, 'y' => 500, 'file' => urlencode($_['directory_path']), 't' => $_['dirToken']))); ?>" class="publicpreview"/>
+					<img src="<?php p(OCP\Util::linkToRoute( 'core_ajax_public_preview', array('x' => 128, 'y' => 128, 'file' => urlencode($_['directory_path']), 't' => $_['dirToken']))); ?>" class="publicpreview"/>
 				</div>
 			<?php endif; ?>
 			<div class="directDownload">