Paste this snippet into your child theme’s functions.php to render the stream via [media_reels_funnel]:

function render_media_stream_funnel($atts) {
    ob_start();
    ?>
    <div class="snap-stream h-[100dvh] w-full overflow-y-scroll snap-y snap-mandatory">
      <?php if( have_rows('stream_slides') ): ?>
        <?php while( have_rows('stream_slides') ): the_row(); ?>
          <div class="snap-card snap-start relative h-full w-full">
            <img src="<?php echo esc_url(get_sub_field('media_file')['url']); ?>" class="w-full h-full object-cover" />
            <div class="absolute bottom-6 left-5 right-5 z-20">
              <h3 class="text-white font-bold text-lg"><?php the_sub_field('title'); ?></h3>
              <button class="funnel-cta bg-pink-600 text-white font-bold px-4 py-2 rounded-xl">
                <?php the_sub_field('cta_label'); ?>
              </button>
            </div>
          </div>
        <?php endwhile; ?>
      <?php endif; ?>
    </div>
    <?php
    return ob_get_clean();
}
add_shortcode('media_reels_funnel', 'render_media_stream_funnel');

Registration definition for a custom WordPress Gutenberg block using block.json:

{
  "$schema": "https://schemas.wp.org/trunk/block.json",
  "apiVersion": 3,
  "name": "funnel/reels-stream",
  "title": "TikTok Style Media Stream Funnel",
  "category": "media",
  "icon": "format-video",
  "description": "Fullscreen vertical snapping image funnel with interactive conversion drawer.",
  "supports": {
    "align": ["full"],
    "html": false
  },
  "attributes": {
    "autoPlayInterval": { "type": "number", "default": 5000 },
    "enableSoundEffects": { "type": "boolean", "default": true }
  },
  "editorScript": "file:./index.js",
  "render": "file:./render.php"
}