How can I add a separate video in the video block section for mobile (Dawn Theme)

Topic summary

  • Goal: Add a separate mobile video source for the Dawn theme’s video section (not the banner/hero) in Shopify.

  • Background: The poster successfully added separate desktop/mobile videos for the banner using a YouTube tutorial and wants the same capability for the video block used on the homepage.

  • Problem: A landscape desktop video is being cropped in the square-ish mobile view, producing an unprofessional look. They want distinct uploads for desktop and mobile to avoid relying on centered framing.

  • Request: Clear instructions on how to create the extra setting/section in the theme editor, the required custom code, and exactly where to place it in the theme files.

  • Visuals: A screenshot was provided to show the current mobile result of the video block.

  • Status: No solution or guidance provided yet; the request remains open.

Summarized with AI on January 2. AI used: gpt-5.

I am looking for information on how to add a section in the Dawn theme editor plus whatever custom coding in order to add a separate video for mobile (for the video block section, not the banner). I was able to do this for the banner by finding a YouTube tutorial from a coder/YouTuber and it worked great, but I also need to do the same for the video block. I use the video block for a promotional video on my home page, and I don’t like how it is showing up on mobile … since the destop size is wide and the mobile view is square, it doesn’t look professional to have a “cropped out” version of the desktop video showing on the mobile screen. Also, I don’t like having to create a landscape video for desktop and make sure that the center part is viewable on mobile. In my view, there should be a separate section to upload separate videos for both devices in the Dawn theme editor, in order to give a great user experience for the customer on the website, regardless of which device they are using.

If you could give me instructions on how to add the section in the theme, plus the coding and where to put it, that would be greatly appreciated! I asked the original YouTuber this question but have not yet received a response, and it was quite a while ago.

Thanks in advance!

I have what it looks lime here …