Render the JSMPEG spinner until the last possible moment.

src/scss/media-carousel.scss

@@ -2,6 +2,12 @@
   --video-max-height: none;
 }
 
+
+.embla__container {
+  // To support adaptive height animations.
+  transition: max-height 0.5s ease;
+}
+
 .embla__slide {
   flex: 0 0 100%;
 }