Fix: add attribute merging

src/Element/ImageSizes.php

@@ -65,6 +65,9 @@ class ImageSizes extends RenderElement {
       ],
       'data-src-fallback' => static::getFallBackStyle($uri, $style),
     ];
+    if (isset($element['#attributes'])) {
+      $attributes = array_merge($element['#attributes'], $attributes);
+    }
     if (isset($element['#alt'])) {
       $attributes['alt'] = $element['#alt'];
     }